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Mammalian physiology is exquisitely tuned to anticipate and synchronize with environmental oscillations. These oscillations appear to occur in a networked fashion across systems and timescales, such that information about difficult-to-measure systems (e.g., reproductive) may be garnered from easy-to-measure systems (e.g., autonomic, and thermoregulatory). These network dynamics and their implications for health require deep exploration. The goals of this dissertation are to 1) investigate the relationship among reproductive, metabolic, and autonomic rhythms at the hourly to ovulatory timescales, and 2) investigate the conditions under which peripheral timeseries features may serve as proxies for hormonal status. This dissertation traverses discrete stages of reproductive life: adolescence, adulthood, and menopause; as well as the impacts of exogenous network perturbations at each stage of life. Chapter 1 reviews central mechanisms of coupled oscillations in the reproductive and thermoregulatory systems. Chapters 2 and 3 investigate the development of thermoregulatory rhythms across adolescence, their dependence on endogenous and exogenous reproductive hormones, their interaction with natural and artificial environments, and derive peripheral features to monitor reproductive development in the rat. Chapter 4 extends these findings to adult women and investigates shared rhythmicity among autonomic and thermoregulatory outputs and sex hormones for the purposes of LH surge prediction or identification of its absence in menopause. With an eye toward future developments in sex hormone replacement, Chapter 5 compares the effects of the most advanced forms of continuous hormone replacement therapy on biological rhythms in metabolic output. These studies inform our understanding of the structure of reproductive, metabolic, and autonomic networks across life, and reveal translational tools for reproductive health.

Are ovulatory cycle shifts in women's mate attraction and preferences robust? What are underlying mechanisms of potential cycle shifts? These questions are the subject of a current scientific debate surrounding the good genes ovulatory shift hypothesis. Here, we report a large, preregistered, within-subjects study, including salivary hormone measures and conception risk estimates based on luteinizing hormone tests. In four sessions across one ovulatory cycle, N = 257 women (= 1028 sessions) rated the attractiveness of 40 natural male bodies, 40 natural female bodies and 40 objects. Multilevel analyses yielded weak evidence for ovulatory increases in women's general attraction, specifically to male bodies, though they are not systematically related to changes in steroid hormone levels. Further, we found no compelling robust evidence for mate preference shifts across the cycle, as only one out of many different tests showed some weak evidence for such effects. Mechanisms regulating cycle shifts, the impact of our results on developing and revising cycle shift theories, and influences of different methodologies on results are discussed.

We studied age-related changes in the ovulatory function in rats subjected to light deprivation and treated with the blocker of the melatonin receptors Luzindol. A cytological study of the estrus cycle was performed quarterly for 2 years. We found that, under conditions of light deprivation, age-related changes in the ovulatory cycle appeared later on and were less expressed than those observed in control females housed under standard light conditions. Blocking of the melatonin receptors with Luzindol did not significantly modified time course of aging as compared to the control group housed under standard lighting.

Objective Determine the interrelations between reductions in energy availability (EA), luteinizing hormone (LH) pulse frequency, and the induction of menstrual disturbances in previously sedentary, ovulatory women. Methods Secondary analysis of a randomized controlled trial consisting of a 3-month controlled diet and supervised exercise program. EA was calculated daily by measured energy intake (kcal) and exercise energy expenditure (kcal) normalized to fat-free mass (kg) and averaged during baseline and each of 3 intervention menstrual cycles. Blood samples were obtained every 10 minutes for 24 hours in the early follicular phase before the intervention and after 3 months of diet and exercise (n = 14). LH pulse dynamics were assessed by Cluster. Linear mixed models determined whether EA predicts LH pulse frequency and LH pulse frequency predicts luteal phase defects (LPDs). Results Subjects were 20 ± 1 years old, 165.1 ± 1.4 cm tall, and weighed 58.9 ± 1.5 kg. LH pulse frequency decreased from 0.82 ± 0.06 pulses/h to 0.63 ± 0.09 pulses/h (P = 0.048) as a result of the intervention which produced modest (-3.2 ± 0.6 kg) weight loss. EA, averaged across a menstrual cycle, predicted LH pulse frequency (P = 0.003) such that a single-unit decrease in EA was associated with a 0.017 pulses/h decrease in LH pulse frequency. LH pulse frequency in cycles with LPDs was 49% of that observed in cycles with no menstrual disturbances and for every 0.1-unit decrease in LH pulse frequency, the odds of having an LPD were 22× greater than having an optimal ovulatory cycle (P = 0.01). Conclusions Modest reductions in EA over a prolonged period are associated with decreased LH pulse frequency and the induction of menstrual disturbances.

Controlled ovarian hyperstimulation (COH), followed by ovulatory induction, is essential in assisted reproduction technology (ART) procedures. In a physiological ovulatory cycle, ovulation results from the joint action of follicle-stimulating hormone (FSH) and luteinizing hormone (LH).

Across human societies and many nonhuman animals, males have greater interest in uncommitted sex (more unrestricted sociosexuality) than do females. Testosterone shows positive associations with male-typical sociosexual behavior in nonhuman animals. Yet, it remains unclear whether the human sex difference in sociosexual psychology (attitudes and desires) is mediated by testosterone, whether any relationships between testosterone and sociosexuality differ between men and women, and what the nature of these possible relationships might be. In studies to resolve these questions, we examined relationships between salivary testosterone concentrations and sociosexual psychology and behavior in men and women. We measured testosterone in all men in our sample, but only in those women taking oral contraception (OC-using women) in order to reduce the influence of ovulatory cycle variation in ovarian hormone production. We found that OC-using women did not differ from normally-ovulating women in sociosexual psychology or behavior, but that circulating testosterone mediated the sex difference in human sociosexuality and predicted sociosexual psychology in men but not OC-using women. Moreover, when sociosexual psychology was controlled, men's sociosexual behavior (number of sexual partners) was negatively related to testosterone, suggesting that testosterone drives sociosexual psychology in men and is inhibited when those desires are fulfilled. This more complex relationship between androgens and male sexuality may reconcile some conflicting prior reports.

Exhaustive exercises can cause delayed menarche or menstrual cycle irregularities in females. Omega-3 polyunsaturated fatty acids (ω-3 PUFAs) are incorporated into a wide range of benefits in many physiological systems. Our work aimed to assess the role of ω-3 PUFA docosahexaenoic acid (DHA) on the deleterious effects of exhaustive exercise on the female reproductive system in rats. Virgin female rats were randomly divided into 4 groups (12 rats in each): control group, omega-3 group treated with DHA, exhaustive exercise group, and exhaustive exercised rats treated with DHA. Omega-3 was given orally to the rats once daily for 4 estrous cycles. Exhaustive exercises revealed lower levels in progesterone and gonadotropins together with histopathological decrease in number of growing follicles and corpora lutea. Moreover, the exercised rats showed low levels of ovarian antioxidants with high level of caspase-3 and plasma cortisol level that lead to disruption of hypothalamic–pituitary–gonadal axis. ω-3 PUFA DHA has beneficial effects on the number of newly growing follicles in both sedentary and exercised rats with decreasing the level of caspase-3 and increasing the antioxidant activity in ovaries. Exhaustive exercises can cause ovulatory problems in female rats that can be improved by ω-3 supplementation.

Background Females are markedly underinvestigated in the biological and behavioral sciences due to the presumption that cyclic hormonal changes across the ovulatory cycle introduce excess variability to measures of interest in comparison to males. However, recent analyses indicate that male and female mice and rats exhibit comparable variability across numerous physiological and behavioral measures, even when the stage of the estrous cycle is not considered. Hormonal changes across the ovulatory cycle likely contribute cyclic, intra-individual variability in females, but the source(s) of male variability has, to our knowledge, not been investigated. It is unclear whether male variability, like that of females, is temporally structured and, therefore, quantifiable and predictable. Finally, whether males and females exhibit variability on similar time scales has not been explored. Methods These questions were addressed by collecting chronic, high temporal resolution locomotor activity (LA) and core body temperature (CBT) data from male and female BALB/c mice. Results Contrary to expectation, males are more variable than females over the course of the day (diel variability) and exhibit higher intra-individual daily range than females in both LA and CBT. Between mice of a given sex, variability is comparable for LA but the inter-individual daily range in CBT is greater for males. To identify potential rhythmic processes contributing to these sex differences, we employed wavelet transformations across a range of periodicities (1–39 h). Conclusions Although variability in circadian power is comparable between the sexes for both LA and CBT, infradian variability is greater in females and ultradian variability is greater in males. Thus, exclusion of female mice from studies because of estrous cycle variability may increase variance in investigations where only male measures are collected over a span of several hours and limit generalization of findings from males to females.

This research was designed to study the profile of the hormones estriol, progesterone, in the blood during a cycle of ovulation in controlled laying hens and laying hens that treated by giving the turmeric powder. Determination of hormone profile was done on laying hens. Six laying hens aged 20 month were divided into two experimental unit. Each experimental unit consist of three laying hens i.e., P0: control (not supplemented with turmeric powder), P1: turmeric powder supplementation at a dose of 405 mg/laying hens/day for a month. Blood was drawn via jugular vein by 4 mL. Blood sampling performed every 2 h starting after hen lay eggs during a cycle of ovulation, then retrieved and analyzed the serum levels of estrogen and progesterone. The data graphed to determine the profile of the hormones estrogen, progesterone and compared between the controlled and the treated with turmeric powder. The results showed that administration of turmeric powder can shorten the cycle of ovulation about 5 h 35 min. Turmeric powder did not affect the pattern of fluctuations in the hormone progesterone. There are 4 progesterone peaks during the first cycle of ovulation both in controlled laying hens and laying hens that treated with turmeric powder. There was a change to the hormone estriol fluctuations. In controlled laying hens takes four peaks hormone estriol in an ovulatory cycle, whereas in laying hen treated with turmeric powder was 1 hormone estriol peak occurring approximately 15 h before ovulation.

Women in the fertile phase of their menstrual cycle show an enhanced sexual preference for masculine expressions in behavioral, morphological and scent traits. These masculinity preferences may be associated with testosterone (T) levels in males and hence connote male quality as a sire. Thus, a scent preference of fertile-phase women for T is predicted. A recent study, however, found no evidence for this, but reported that women prefer the scent of men with high cortisol (C). That study had low power to detect the predicted effect, as well as other methodological limitations. We tested women's preferences across their ovulatory cycle for the body scent of men who varied in T and C, using a larger sample of men and methods used in research on cycle preferences for symmetry-related male body scent. Conception risk in the cycle positively predicted women's scent ratings of men's T; scent ratings of C or T × C interaction were not robustly related to conception risk. Conception risk is related positively to a preference for scent of men's symmetry. This preference is distinct from that arising from a preference for the scent of T. The male-emitted chemical(s) responsible for these preferences shifts across women's cycle remain unknown.

In many species, females are more sexually attractive to males near ovulation. Some evidence suggests a similar pattern in humans, but methodological limitations prohibit firm conclusions at present, and information on physiological mechanisms underlying any such pattern is lacking. In 202 normally-cycling women, we explored whether women's attractiveness changed over the cycle as a function of two likely candidates for mediating these changes: estradiol and progesterone. We scheduled women to attend one session during the late follicular phase and another during the mid-luteal phase. At each session, facial photographs, voice recordings and saliva samples were collected. All photographs and voice recordings were subsequently rated by men for attractiveness and by women for flirtatiousness and attractiveness to men. Saliva samples were assayed for estradiol and progesterone. We found that progesterone and its interaction with estradiol negatively predicted vocal attractiveness and overall (facial plus vocal) attractiveness to men. Progesterone also negatively predicted women's facial attractiveness to men and female-rated facial attractiveness, facial flirtatiousness and vocal attractiveness, but not female-rated vocal flirtatiousness. These results strongly suggest a pattern of increased attractiveness during peak fertility in the menstrual cycle and implicate estradiol and progesterone in driving these changes.

The captive breeding program of the Okinawa rail started in 2008. For successful captive breeding, information related to reproduction, such as age at sexual maturity, testicular cycles and ovulatory cycles, is essential to predict when reproduction is possible and when certain reproductive behaviors are most likely to occur. We made gross and histological observations of the reproductive organs of Okinawa rails to gain understanding of sexual maturity, the testicular cycle and the ovulatory cycle. We found that the weight of the testis was smallest in December and largest in March. Changes in the diameter of the seminiferous tubule showed the same pattern. Mature sperm were observed from March to June. The heaviest ovary was observed in April. A single peak of reproduction, from March to April, was observed in males and females. Our observations suggested that the Okinawa rail is a seasonal breeder. Establishing suitable breeding pairs will be critical to ensure success of the Okinawa rail captive breeding program. Our results suggested that pairing must be started before March. If supportive breeding is used, semen should be collected from March to June and artificial insemination conducted in April.

To date, our understanding of the function of testosterone in female reproductive physiology is only marginal although there are indications that testosterone is involved in modulating follicular recruitment, growth, atresia, and ovulation. Studies elevating testosterone in breeding female birds have, in most instances, found detrimental effects, such as delayed clutch initiation or decreased clutch size. In our previous study, testosterone treatment of female homing pigeons delayed clutch initiation without diminishing fecundity. In this study, we explore whether the observed effect might have been caused by testosterone influencing follicle maturation or ovulation. We implanted mature female pigeons with testosterone prior to pairing, which resulted in constant elevation of circulating testosterone concentrations within the physiological range. We killed females after they had laid the first egg and measured ovarian and follicular development. Ovarian mass and pre-hierarchical yolky follicles were not affected by the treatment; however, testosterone females produced smaller and lighter preovulatory follicles. High plasma testosterone levels at oviposition or a strong temporal increase in testosterone were negatively related to mass and diameter of second follicles. We proposed that sustained elevation of testosterone delays follicular maturation, potentially via negative feedback on the hypothalamo-pituitary‐gonadal axis. Furthermore, to gain better insight into the regulation of yolk hormone acquisition, we measured testosterone concentrations in the preovulatory follicles. We found no differences between treatment groups but follicle yolk contained much higher levels of testosterone than yolk of unincubated eggs, suggesting that hormone measurements performed after oviposition do not correctly reflect maternal allocation. J. Exp. Zool. 313A:328–338, 2010. & 2010 Wiley-Liss, Inc. How to cite this article: Goerlich VC, Dijkstra C, Groothuis TGG. 2010. Effects of in vivo testosterone manipulation on ovarian morphology, follicular development, and follicle yolk testosterone in the homing pigeon. J. Exp. Zool. 313A:328–338.

Serial changes of serum CA125 levels during 32 menstrual cycles were examined in 32 healthy young women (19-21 years of age) charting basal body temperature (BBT) and measuring serum estradiol and progesterone levels. Analysis of BBT charts and serum progesterone levels revealed that the 32 menstrual cycles could be classified into either an ovulatory cycle with a sustained BBT temperature increase for at least 10 days (type I: 9 cycles), an ovulatory cycle with a sustained BBT temperature increase for less than 10 days (type II: 17 cycles), or anovulation (type III: 6 cycles). All 32 cycles exhibited basal CA125 levels of less than 35 u/ml throughout the cycle, except during the period of menstruation. At menstruation, 7 of the 9 cycles of type I showed a marked, transient elevation of CA125 levels from previous basal levels (a mean net increase). On the other hand, 12 of 17 cycles of type II showed only a slight elevation of CA125 levels during the period of menstruation. None of the 6 cycles of type III showed any apparent increase in CA125 levels during the period of menstruation. The mean net increase of CA125 levels during the period of menstruation in the cycles of type I was significantly higher than that of the cycles of type II (p less than 0.05) and type III (p less than 0.05). These results imply that a transient elevation of serum CA125 levels during the period of menstruation occurs in cycles with ovulation, and the levels of elevation seem to be closely associated with the duration of the sustained BBT temperature increase.

This study attempted to clarify the difference in eggshell pigmentation between blue-shelled ducks (BSD) and white-shelled ducks (WSD). The eggshell pigmentation deposition process is discussed. Ultraviolet spectro-photometer and HPLC were used to determine the biliverdin concentration in the shell gland, uterus liquid and eggshell at 6, 12, 18, 20, 23.5 h post-oviposition. The biliverdin concentration in the eggshell and uterus fluid showed significant differences between BSD and WSD, but not in the shell gland. The heme oxygenase activity in the shell gland of both kinds of ducks remained mostly constant during the ovulatory cycle with no variation. The assay of exogenous biliverdin injection into the shell gland antrum in the WSD indicated that exogenous biliverdin could be deposited continuously into the eggshell until the source was exhausted. A layer-by-layer dissolution assay was used to examine the eggshell pigment deposition process. The biliverdin concentration in the first to sixth layers of the eggshell in the BSD was significantly higher than that in the white-shelled counterpart. The blue pigment concentration increased persistently from the 6 th layer to the 1 st layer. The BSD eggshells did not accumulate a large quantity of biliverdin in the most external layer. They tended to increase the deposition layer by layer. Our results demonstrated that different BSD and WSD eggshell colors were influenced by the amount of biliverdin in the uterus fluid and not determined by the amount of biliverdin in the shell gland. This implies the existence of a mechanism that controls biliverdin transportation from the shell gland into the uterus fluid, thereby playing a key role in regulating duck eggshell color.

We have studied the interplay of hypothalamus-pituitary and ovarian cancer for three months in three cases of young women with dysfunctional uterine bleeding, by radioimmunoassays serial plasma determinations of FSH, LH, estradiol and progesterone. In 2 patients novulatorios cycles were observed even after administration of clomiphene citrate, presenting at least partial failure, LH surge in response to sharp increases, although irregular, estradiol, follicle from additional secretion. In a probable case it was presented spontaneous ovulatory cycle and then induced by clomiphene. In turn, plasma elevations of LH and FSH, found during treatment with clomiphene and subsequent follicular development, indicate that remained intact negative feedback mechanism between estrogen and the gonadotropins. Judging from these findings, it seems that there are changes in the sensitivity of the hypothalamus, from cycle to cycle, dysfunctional uterine bleeding in adolescence Se ha estudiado la interrelación de hipotálamo-hipófisis y ovario durante tres meses, en tres casos de mujeres jóvenes con hemorragia uterina disfuncional, mediante determinaciones radioinmunológicas seriados en plasma de FSH, LH, estradiol y progesterona. En 2 de las pacientes se observaron ciclos a novulatorios, incluso después de administrar citrato de clomifeno, presentándose falla al menos parcial, en la descarga de LH como respuesta a los marcados incrementos, aunque irregulares, del estradiol, procedente de secreción folicular adicional. En un caso se presentó probable ciclo ovulatorio espontáneo y después inducido por clomifeno. A su vez, las elevaciones plasmáticas de LH y FSH, encontradas durante el tratamiento con el clomifeno y subsiguiente desarrollo folicular, indicarían que se mantuvo indemne el mecanismo del feedback negativo entre el estrógeno y las gonadotrofinas. A juzgar por estos hallazgos, pareciera que hay cambios en la sensibilidad del hipotálamo, de ciclo a ciclo, en la hemorragia uterina disfuncional de la adolescencia.

In the hen ovary, each preovulatory follicle in the hierarchy, irrespective of its size and the level of its maturity is exposed to the preovulatory LH surge in each ovulatory cycle of an egg laying sequence. In the present study, the thecal weight and membrane protein content of theca layers at different stages of hen ovulatory cycle were assessed. Hens were killed 2 h (stage I), 9 h (stage II), 16 h (stage III), and 23 h (stage IV) after oviposition. The first (F1), second (F2), third (F3), fourth (F4) and fifth (F5) largest yellow follicles were utilized. In all follicles except F1, the thecal weight rose considerably between stages I and III (P < 0.05) followed by a slight cessation of the thecal growth at stage IV. The mean content of the theca membrane protein in F1-F5 follicles was lowest at stage III, increasing at stage IV (P < 0.05), although, in the case of individual follicles the difference was significant (P < 0.05) in F3 follicles only. Estradiol-17beta levels in the plasma were lowest (but not significant) at stage III, and a fourfold increase in the plasma progesterone concentration occurred at stage IV. These findings demonstrate for the first time the ovulatory cycle-related alterations in the thecal weight and membrane protein content in the hen preovulatory follicles. Data suggest that the preovulatory rise in ovarian steroid hormones is probably involved in transient termination of the growth and induction of differentiation of the theca in preovulatory follicles as they pass from one category to the next.

Although the most well-known function of vascular endothelial growth factor is its angiogenic activity, it plays more than a simple angiogenic role in the female reproductive system as it is involved in a number of key events in the course of the ovulatory cycle. The modulation of vascular endothelial growth factor expression varies in different reproductive tissues, probably related to its various functions at these different sites.

The present study was undertaken to determine changes in circulating levels of immunoreactive (ir)-inhibin, FSH, LH, estradiol-17beta, progesterone, and testosterone during the ovulatory cycle of Shao ducks. Serial blood samples were taken from two groups of laying ducks for measurement of ir-inhibin, gonadotropins, and steroid hormones at 2 h intervals for 24 h. Plasma concentrations of ir-inhibin did not change significantly during the ovulatory cycle. The highest level of plasma ir-inhibin was observed 6 h prior to ovulation, which coincided with a decreased level of plasma FSH. One FSH surge was found 12 h after ovulation. Estradiol-17beta, progesterone, and testosterone were also determined during the ovulatory cycle. Two peak values were detected for estradiol-17beta 8 h before ovulation and 4 h after ovulation, while progesterone started to increase 4 h before ovulation and reached a peak at ovulation. The highest level of plasma testosterone was detected around the time of ovulation. These results suggest that inhibin may be involved in the control of FSH secretion during the ovulatory cycle. In addition, both LH and progesterone are of importance in the ovulation process of Shao ducks.

We describe the in vivo features of endometrium stained with methylene blue dye and observed via microhysteroscopy, showing the patterns of endometrial glands and superficial cell changes during the midproliferative, periovulatory, and midluteal phases. These preliminary observations have allowed us to identify a series of changes occurring in the different phases of the ovulatory cycle of potential value in reproductive medicine for specific groups of infertile patients.

The aim of this study was to compare the profile of circulating concentrations of LH, progesterone and oestradiol in a multiple ovulating male line with that of a single ovulating line of traditional turkeys. Plasma samples from seven traditional and 12 male-line turkeys were obtained every 3 h for 36 h. Male-line and traditional turkeys had single peaks of LH and progesterone that were of similar duration in both lines. The mean height of the plasma peaks of LH and progesterone were similar in the two lines and there was no detectable peak plasma oestrogen concentration. Mean plasma concentrations of LH and oestrogen were higher in single compared with multiple ovulating turkeys, whereas there were no differences in mean plasma progesterone concentrations. The results indicate that the multiple ovulation state in genetically selected high-growth lines of turkey may be the result of a correlated response in the steroidogenic capacity of ovarian tissue associated with low plasma concentrations of oestrogen rather than of a disturbance in the hormone profile of the ovulatory cycle.

In the preovulatory follicle, the LH surge stimulates progesterone production, reduces estradiol synthesis, and scales up the permeability of the blood-follicle barrier. The purpose of this study was to investigate whether the extent of these changes is correlated with the levels of estradiol, estradiol esters, and cholesteryl esters in the follicular fluid. The follicular levels of progesterone, estradiol, estradiol linoleate, cholesterol, and cholesteryl linoleate were measured by HPLC. The estradiol linoleate/estradiol ratio, which reflects the efficiency of in vivo estradiol esterification, and the cholesteryl linoleate/cholesterol ratio were calculated and found negatively correlated. The estradiol level was positively correlated with the cholesteryl linoleate/cholesterol ratio while negatively correlated with the estradiol linoleate/estradiol ratio. The in vitro activity of lecithin-cholesterol acyltransferase, the enzyme esterifying both cholesterol and estradiol, was assayed by incubating the fluid with labeled substrates. This activity was not correlated with either the estradiol linoleate/estradiol or the cholesteryl linoleate/cholesterol ratio. The enzyme K m and V max values were lower with estradiol than with cholesterol. Higher estradiol linoleate/estradiol ratios and lower cholesteryl linoleate/cholesterol ratios were associated with higher level of Haptoglobin penetration into the follicle. This level, which was determined by ELISA, was found increased with increased progesterone concentration and, therefore, used as a marker of the LH-stimulated permeability of the blood-follicle barrier. Our data suggest that early preovulatory follicles contain more cholesteryl esters and less estradiol esters than follicles closer to ovulation.

Follicular growth of ruminant species occurs more than once during an estrous cycle either resulting in ovulation (ovulatory follicular wave) or not resulting in ovulation (latent follicular wave). Using Shiba-goats, we examined if ovulation could be induced from every latent follicular wave and if the resulting ova were fertile. Ovarian follicular development was monitored daily by transrectal ultrasonographic examination in 20 female goats for 2 consecutive estrous cycles. After the second spontaneous ovulation (day 0 = ovulation), all animals were each treated with a luteolytic dose of prostaglandin F2α (PGF 2α) on days 3 and 4,which resulted in ovulation from the first latent wave. Fertile males goats (n=2) were immediately introduced to the first group of animals (n=5), resulting in 4 pregnancies. For the second group of goats (n=9), 4 consecutive short estrous cycles were induced by the PGF2 α treatment at a mean interval of 6.5 ± 1.2 days with a range of 4-9 days. Five of 9 goats were allowed to mate following 4 consecutive short ovulatory cycles; normal behavioral estrus was observed at each estrus, and four of five animals became pregnant. The third group of goats (n=6), in addition to PGF2α treatment, received exogenous progesterone supplement which allowed latent follicular development to occur, but prevented ovulation until the effect of progesterone supplement subsided. These results suggest that female Shiba-goats possess physiological mechanisms for the final steps of follicular maturation and subsequent ovulation at short intervals when progesterone production from the newly developed corpus luteum is terminated.

With the ultimate goal of identifying a consensus bioactive conformation of GnRH antagonists, the compatibility of a number of side chain to side chain bridges in bioactive analogues was systematically explored. In an earlier publication, cyclo[Asp(4)-Dpr(10)]GnRH antagonists with high potencies in vitro and in vivo had been identified.(1) Independently from Dutta et al. (2) and based on structural considerations, the cyclic [Glu(5)-Lys(8)] constraint was also found to be tolerated in GnRH antagonists. We describe here a large number of cyclic (4-10) and (5-8) and dicyclic (4-10/5-8) GnRH antagonists optimized for affinity to the rat GnRH receptor and in vivo antiovulatory potency. The most potent monocyclic analogues were cyclo(4-10)[Ac-DNal(1), DFpa(2),DTrp(3),Asp(4),DArg(6),Xaa(10)]GnRH with Xaa = D/LAgl (1, K(i) = 1.3 nM) or Dpr (2, K(i) = 0.36 nM), which completely blocked ovulation in cycling rats after sc administration of 2.5 microgram at noon of proestrus. Much less potent were the closely related analogues with Xaa = Dbu (3, K(i) = 10 nM) or cyclo(4-10)[Ac-DNal(1), DFpa(2),DTrp(3),Glu(4),DArg(6),D/LAgl(10)]GnRH (4, K(i) = 1.3 nM). Cyclo(5-8)[Ac-DNal(1),DCpa(2),DTrp(3),Glu(5),DArg++ +(6),Lys(8), DAla(10)]GnRH (13), although at least 20 times less potent in the AOA than 1 or 2 with similar GnRHR affinity (K(i) = 0.84 nM), was found to be one of the most potent in a series of closely related cyclo(5-8) analogues with different bridge lengths and bridgehead chirality. The very high affinity of cyclo(5,5'-8)[Ac-DNal(1), DCpa(2),DPal(3),Glu(5)(betaAla),DArg(6),(D or L)Agl,(8)DAla(10)]GnRH 14 (K(i) = 0.15 nM) correlates well with its high potency in vivo (full inhibition of ovulation at 25 microgram/rat). Dicyclo(4-10/5-8)[Ac-DNal(1),DCpa(2),DTrp(3),Asp (4),Glu(5),DArg(6), Lys(8),Dpr(10)]GnRH (24, K(i) = 0.32 nM) is one-fourth as potent as 1 or 2, in the AOA; this suggests that the introduction of the (4-10) bridge in 13, while having little effect on affinity, restores functional/conformational features favorable for stability and distribution. To further increase potency of dicyclic antagonists, the size and composition of the (5-8) bridge was varied. For example, the substitution of Xbb(5') by Gly (30, K(i) = 0.16 nM), Sar (31, K(i) = 0.20 nM), Phe (32, K(i) = 0.23 nM), DPhe (33, K(i) = 120 nM), Arg (36, K(i) = 0.20 nM), Nal (37, K(i) = 4.2 nM), His (38, K(i) = 0.10 nM), and Cpa (39, K(i) = 0.23 nM) in cyclo(4-10/5,5'-8)[Ac-DNal(1),DCpa(2),DPal(3),Asp(4),G lu(5)(Xbb(5')), DArg(6),Dbu,(8)Dpr(10)]GnRH yielded several very high affinity analogues that were 10, ca. 10, 4,200, 1, ca. 4,2, and 2 times less potent than 1 or 2, respectively. Other scaffolds constrained by disulfide (7, K(i) = 2.4 nM; and 8, K(i) = 450 nM), cyclo[Glu(5)-Aph(8)] (16, K(i) = 20 nM; and 17, K(i) = 0.28 nM), or cyclo[Asp(5)-/Glu(5)-/Asp(5)(Gly(5'))-Amp(8)] (19, K(i) = 1.3 nM; 22, K(i) = 3.3 nM; and 23, K(i) = 3.6 nM) bridges yielded analogues that were less potent in vivo and had a wide range of affinities. The effects on biological activity of substituting DCpa or DFpa at position 2, DPal or DTrp at position 3, and DArg, DNal, or DCit at position 6 are also discussed. Interestingly, monocyclo(5-8)[Glu(5), DNal(6),Lys(8)]GnRH (18, K(i) = 1. (ABSTRACT TRUNCATED)

The processes that precisely control the selection of ovulatory follicles from a growing cohort are poorly understood. This reduction in follicle number occurs through several phases of selection, consequently we limit the use of the term ‘selection’ to the first major reduction of growing follicles, at the pre- to early antral stage. The final process of selectio n, achieving the appropriate ovulatory number, is referred to as ‘dominance’. We discuss possible mechanisms that could bring about these reductions and highlight intra-ovarian involvement, particularly via follicle‐follicle interactions. Analogies are drawn between local ovarian events and processes commonly reported in the determination of cell fate in developmental biology. Two facets of intra-follicular interactions are proposed: initially that follicle‐follicle interactions mediate early selection processes at the preantral stage, and later that during antral development dominant follicles directly affect the fate of the subordinate cohort members.

Racial differences in renal kallikrein excretion: Effect of the ovulatory cycle.BackgroundRenal kallikrein excretion is diminished in essential hypertension, especially in African-Americans, and evidence exists for a major gene effect on the kallikrein phenotype. In addition, urinary kallikrein excretion differs by gender, with ovulating females having greater kallikrein excretion than males or postmenopausal females. Recent studies have shown that renal kallikrein excretion varies in females during the ovulatory cycle, with levels rising during the luteal phase and returning during the follicular phase to levels that are similar to those of males. In family studies, gender differences in urinary kallikrein excretion were present in white subjects, but not black subjects. We therefore hypothesized dysregulation of kallikrein biosynthetic responses in African-Americans.MethodsWe determined urinary kallikrein activity [chromogenic substrate S2266 (D-val-leu-arg-paranitroanilide) assay; in μU/mg creatinine] in white (N = 15) and black (N = 11) ovulating females during the ovulatory cycle. Serum progesterone, estrogen, plasma renin activity as well as urinary aldosterone, and urinary electrolytes were determined to investigate changes between mid-follicular and mid-luteal phases in the two groups.ResultsWhite and black groups were matched for age, body mass index, blood pressure, heart rate and renal function. Ovulatory cycle phases were confirmed by serum progesterone determinations, which increased significantly in whites and blacks to a comparable degree [0.84 ± 0.14nmol/liter (mid-follicular) to 29.77 ± 4.70nmol/liter (mid-luteal) in whites, 0.67 ± 0.08nmol/liter (mid-follicular) to 28.62 ± 5.83nmol/liter (mid-luteal) in blacks; P < 0.001 for cycle effect, P = NS for race effect and race X cycle interaction]. Urinary kallikrein activity increased from 623 ± 86 μU/mg creatinine (mid-follicular) to 948 ± 142 μU/mg creatinine (mid-luteal) in whites, but did not change in blacks during the ovulatory cycle [239 ± 73 μU/mg creatinine (mid-follicular] to 244 ± 41 μU/mg creatinine (mid-luteal)]. Two-way ANOVA revealed significant effects on urinary kallikrein for race (P < 0.001), cycle (P < 0.05), and race X cycle interaction (P < 0.05). Thus, white females had higher urinary kallikrein than black females, and demonstrated a significant increase in urinary kallikrein excretion during the ovulatory cycle, whereas no significant change in urinary kallikrein activity was seen in the black group. Enzyme kinetic studies and mixing studies demonstrated that these racial differences in renal kallikrein excretion were quantitative, rather than due to qualitative differences in the renal kallikrein enzyme or due to the presence of a kallikrein inhibitor.ConclusionsThese results suggest pronounced blunting of menstrual cycle changes in urinary kallikrein excretion in black females. Blunted urinary kallikrein responses during the ovulatory cycle are consistent with dysregulation of renal kallikrein biosynthetic responses in African-Americans, a group at increased risk for hypertension.

Ovulation and spawning were induced in gilthead seabream, Sparus aurata L., which had failed to spawn spontaneously after thermal manipulations, using a long-acting commercial preparation of leuprolide acetate, an agonist of gonadotropin releasing hormone (GnRHa), in order to study the effects of this treatment on spawning periodicity, the timing of spawning, daily egg production and embryonic viability. Grouped and single females bearing yolky follicles were implanted once with 20, 40 or 80 μg kg−1 (body weight) of GnRHa encapsulated in a biodegradable copolymer, copoly(dl-lactic/glycolic acid ratio of 3:1). All treated females started to spawn after 48 h and about 40% of the eggs were laid during the initial 10-day period with daily peaks of 105 eggs kg−1. The mean daily production of viable eggs ranged between 71–288.102 eggs kg−1. Embryonic viability was equivalent to that of control fish which were induced to spawn with a rise in water temperature. There was, however, a significantly (P < 0.01) higher egg production in the GnRHa-treated fish. While egg laying occurred regularly at dawn in controls, the long-acting GnRHa tended to shorten the normal 24-h ovulatory cycle of seabream, gradually shifting spawning from dawn to sunset. In tanks with single females, sudden spawning readjustments were observed from sunset to dawn through short 12-h ovulatory cycles. Interestingly, spawning of single females with two males resulted in a greater percentage of non-fertilized eggs in comparison to groups of spawning females maintained with a similar ratio of males, presumably as a result of territorial competition when few males try to occupy the same spawning tank.

Changes in luteinizing hormone (LH), progesterone, and testosterone concentrations were determined in blood samples taken every 10 min for 26 hr during an ovulatory cycle in laying turkey hens. During the 26-hr sampling period, one peak of both LH and progesterone and numerous peaks of testosterone were detected. The concentration of LH in plasma increased from basal level (2.44–4.0 ng/ml) to maximum level (8.57–24.3 ng/ml) over 1 to 2 hr and then declined over 3 to 5 hr to a basal level. The duration of the descending portion of the peak was about double that of the ascending portion. The concentration of progesterone increased rapidly from a basal level of 1.18–1.65 ng/ml to a peak of 6.18–11.87 ng/ml and then maintained a plateau before rapidly declining to basal level. The concentration of testosterone increased from a basal level of 0.06–0.09 ng/ml to a peak level of 0.13–0.30 ng/ml. All maximum levels of testosterone preceded those of LH, and all maximum levels of LH preceded those of progesterone. The durations of the progesterone peaks were longer than those of the LH peaks. Progesterone concentrations returned to basal level after LH had returned to basal level, although the initial increase in progesterone concentration was earlier, later, or at the same time as LH. Peak durations of testosterone were variable. The preovulatory surges of LH and progesterone of five of nine sets of samples started at the end of the scotophase and ended during the beginning portion of the photophase. In three of nine sets both the start and the end occurred during the scotophase and in one of nine sets during the photophase. It was concluded from this study that the patterns of secretion of LH, progesterone, and testosterone were similar in that the preovulatory surge was superimposed on a relatively stable basal level, while the temporal relationships of the ovulatory surges of these hormones were variable. The preovulatory surges were more tightly associated with ovulation rather than with photoperiod. Neither progesterone nor testosterone might be an initiator of the LH surge prior to ovulation.

In order to investigate the role of insulin-like growth factors (IGFs) in human ovulation, we evaluated the concentrations of IGF-binding proteins (IGFBPs) in human follicular fluid (FF). The concentrations of IGFBP-1 in the FFs of 15 women undergoing in vitro fertilization and embryo transfer were measured and related to those of 17beta-estradiol (E2), progesterone and androstenedione in the FFs. IGFBP-1 levels in the FFs were positively correlated with those of E2 and progesterone. No correlation was found between the IGFBP-1 and androstenedione levels in FFs. The concentrations of IGFBP-1 were significantly increased in the FFs which contained mature oocytes compared with those of immature oocytes, whereas IGFBP-3 in FFs tended to decrease as oocytes matured. It is suggested that IGFs may play important roles in human preovulatory processes, and that IGFBP-1 may be a valuable biochemical marker in the evaluation of oocytes.

Avian species exhibit a great variety of life-long patterns in reproduction. Many shore birds, such as terns, have relatively long life spans as well as little evidence of reproductive aging. Reproductive aging has been studied extensively in some avian species, primarily in domestic species. In these species, the process of aging is first evidenced by a decline in fertility and reproductive behavior. As the animal continues to age, gonadal function gradually becomes increasingly disrupted leading to cessation of the ovulatory cycle and declining spermatogenesis. Neuroendocrine systems also show evidence of age-related alterations, which affect the function of the gonadotropin releasing hormone (GnRH) system. Moreover, the endogenous patterns in release of GnRH and other hormones appear altered, implying that the age-related changes affect endogenous rhythms that regulate endocrine system function. When integrated with environmental factors and endogenous rhythms, these complex changes in both the neuroendocrine regulatory systems and in gonadal function make triggers of age-related alterations difficult to identify. However, as more data are gathered, the mechanisms underlying these alterations and the factors associated with the process of aging in avian species are being elucidated.

We review our research on the regulation of the mare's ovulatory cycle. We describe the dynamics of GnRH, LH and FSH secretion during the cycle as determined by collecting pituitary venous blood and discuss the central mechanisms involved in generating an ovulatory LH surge. We also consider protocols giving GnRH or its analogues to induce ovulation out-of-season and relate results to the normal control of gonadotropin secretion.

An experiment was carried out to determine whether feeding different calcium levels from the onset of production has an effect on medullary bone reserves, plasma proteins and ultimately shell formation. A total of 80 Single Comb White Leghorn hens photostimulated at 17 wk of age were fed a 2.5% Ca diet until the appearance of the first egg. Thereafter diets providing 2.5, 3.0, 3.5, 4.0, or 4.5% Ca were fed to groups of 16 hens. At 6, 12, 18, or 24 h post-ovrposition, blood was collected from four hens per treatment, which were then euthanized and developing shells and bones sampled. As dietary Ca increased, plasma Ca, protein, and protein-bound phosphorus concentrations also increased (P 0.05) on the % Ca or total Ca content of bone ends or medullary bone. As dietary Ca concentration increased, both shell ash and shell Ca increased (P

When hormones during the ovulatory cycle are shown in phase plane graphs, reported FSH and estrogen values form a specific pattern that resembles the leaning “&" symbol, while LH and progesterone (Pg) values form a "boomerang" shape. Graphs in this paper were made using data reported by Stricker et al. [Clin Chem Lab Med 2006;44:883–887]. These patterns were used to construct a simplistic model of the ovulatory cycle without the conventional "positive feedback" phenomenon. The model is based on few well-established relations: hypothalamic GnRH secretion is increased under estrogen exposure during two weeks that start before the ovulatory surge and lasts till lutheolysis. the pituitary GnRH receptors are so prone to downregulation through ligand binding that this must be important for their function. in several estrogen target tissue progesterone receptor (PgR) expression depends on previous estrogen binding to functional estrogen receptors (ER), while Pg binding to the expressed PgRs reduces both ER and PgR expression. Some key features of the presented model are here listed: High GnRH secretion induced by the recovered estrogen exposure starts in the late follicular phase and lasts till lutheolysis. The LH and FSH surges start due to combination of accumulated pituitary GnRH receptors and increased GnRH secretion. The surges quickly end due to partial downregulation of the pituitary GnRH receptors (64% reduction of the follicular phase pituitary GnRH receptors is needed to explain the reported LH drop after the surge). A strong increase in the lutheal Pg blood level, despite modest decline in LH levels, is explained as delayed expression of pituitary PgRs. Postponed pituitary PgRs expression enforces a negative feedback loop between Pg levels and LH secretions not before the mid lutheal phase. Lutheolysis is explained as a consequence of Pg binding to hypothalamic and pituitary PgRs that reduces local ER expression. When hypothalamic sensitivity to estrogen is diminished due to lack of local ERs, hypothalamus switches back to the low GnRH secretion rate, leading to low secretion of gonadotropins and to lutheolysis. During low GnRH secretion rates, previously downregulated pituitary GnRH receptors recover to normal levels and thus allow the next cycle. Possible implications of the presented model on several topics related to reproductive physiology are shortly discussed with some evolutionary aspects including the emergence of menopause.

An experiment was carried out to investigate rate of shell secretion in two groups of hens selected for differences in shell deformation. Forty 50-wk-old Single Comb White Leghorn hens from two groups shown to produce eggs differing in shell thickness were fed a 3.5% Ca diet. Hens in their third to fifth ovulatory cycle of a sequence were intubated with 15 μCi of 45Ca 0.5 h post-oviposition. At 6, 12, 15 and 24 h, post-intubation blood was collected from five hens, which were subsequently euthanized, and bone samples were taken.Hens producing thick shells had higher (P < 0.05) plasma proteins, although there was no difference (P > 0.05) in plasma Ca or plasma protein-bound phosphorus content. While plasma 45Ca specific activity decreased (P < 0.05) with post-intubation time, there were no differences (P > 0.05) in plasma 45Ca specific activity between the two groups of hens. There were no differences (P > 0.05) in Ca reserves of bone ends or medullary bone alone or combined for hens secreting either thick- or thin-shelled eggs, nor were there any changes (P > 0.05) in these parameters with post-intubation time. Total 45Ca and 45Ca specific activity of both bone ends and medullary bone decreased as the ovulatory cycle proceeded. Regression analysis showed that the rate of depletion of 45Ca from the bone compartment, as indicated by the slope coefficient, was greatest for hens selected to produce thicker shells (Y = 13.8 − 3.11X1, R2 = 0.351, RSD = ± 4.917 for thick-shelled hens; Y = 6.7 − 0.95X1, R2 = 0.360, RSD = 1.1479 for thin shelled hens, where Y is the percentage 45Ca-intubated bone; and X1 is the time in hours). Key words: Calcium, shell formation, bone

OBJECTIVES: New methods for the measurement of the percent free (%FreeP) and percent corticosteroid binding globulin-bound (%CBG-B) fractions of plasma progesterone (P) are described. METHODS: Modifications of previously reported equilibrium dialysis and charcoal adsorption assays were used. P binding was analyzed in single midluteal samples of 16 infertile women with endometrial biopsy proven luteal phase defect (LPD) and 10 infertile women with a normal luteal phase. RESULTS: %FreeP, %CBG-B, percent nonspecific protein-bound P (%NSP), total P and total plasma estradiol (E2) were measured during the normal ovulatory cycles of 5 women. The mean follicular phase %FreeP was found to be lower than in the luteal phase due to a decline in the late follicular phase. This decline correlated with the preovulatory rise in E2. The mean absolute concentration of free P (FreeP) rose significantly in the luteal phase, positively correlating with total P in both phases. Mean %CBG-B and %NSP were unchanged throughout the cycle. P was lower in LPD vs. normal cycles, but %FreeP and %CBG-B were not different. E2 highly correlated with P but not with %FreeP and %CBG-B. CONCLUSIONS: In normal cycles a small but significant decrease in %FreeP occurs in the late follicular phase and is associated with increasing E2. Changes in total P during the ovulatory cycle reflect changes in the concentration of bioactive P. There were no data to support an association of LPD with changes in the bioactive fraction of P.

An investigation was conducted on the ovulatory cycles and pregnancies of captive Banteng cattle (n=4). Estradiol and progesterone profiles plus palpation of the ovaries resulted in a mean cycle length of 20 days (± 0.68) for 6 cycles. Maximum follicle diameter before ovulation ranged from 15 to 20 mm and ovulations occurred equally on the right and left ovaries. Estrous cycles continued year round when not interrupted by pregnancy. Mean latency from parturition to the first ovulation was 44.8 (± 7.8) days, ranging from 30 to 65 days for the 4 pregnancies in 3 of the 4 cows. The fourth cow did not ovulate within the 96-day postpartum sampling period. The results generally conform with those found for the domestic cow (Bostaurus).

The domestic hen with its well-organized follicular hierarchy offers a unique model system for the study of the role of inhibin in follicular development. We have validated a homologous bovine RIA for use in the hen to measure plasma immunoreactive inhibin-like activity during the ovulatory cycle as well as during experimental conditions in which follicular development has been altered. Validation of the bovine RIA kit revealed that increasing amounts of hen plasma gave linear increases in the amount of immunoreactive inhibin detected. This assay system as well as a homologous chicken LH RIA were used to assess plasma concentrations of immunoreactive inhibin and LH, respectively, in experiments 1-3. In experiment 1, blood samples were collected from hens (n = 5) at 2-h intervals for 24 h starting at 1600 h after the lay of the last egg of the sequence through the following day. No significant peak in plasma immunoreactive inhibin level was detected during the ovulatory cycle, in spite of a significant preovulatory rise in plasma LH. The highest level of plasma immunoreactive inhibin was attained, however, 2 h prior to the preovulatory LH surge. In experiment 2, eCG (n = 6) or vehicle (n = 3) was administered to hens daily for 6 days. A blood sample was drawn immediately before injection each day as well as 24 h after the last day of treatment. Treatment with eCG significantly (p < 0.01) raised plasma immunoreactive inhibin-like levels, compared to vehicle-injected controls. In experiment 3, three to four of the largest follicles (F1-F4) were surgically removed, or sham surgery was performed.(ABSTRACT TRUNCATED AT 250 WORDS)

A study was conducted to determine the growth rate of the reproductive organs of breeding female ostriches, which may be used in a prediction model for estimating nutrient requirements of breeders. Forty breeding female ostriches were sampled over an eight week period (five per week) starting at the onset of the breeding season. The ovary and oviducts were collected and weighed at each slaughter interval. No significant trend in the weight of the oviduct of the ostriches could be observed over the 49 d period, this weight being highly correlated with the body weight of the ostrich, whereas the ovary weight tended to be correlated with the time after the onset of the breeding period, although the variation in weights both within and between weights was very high. The variation in the weight of the ovary probably reflects differences in the laying pattern of individuals, and this lends itself to simulating the ovulatory cycle and consequently gaining a better understanding of the process, which would in turn aid in determining the requirement for the nutrients responsible for the growth of the ova.

Summary Ionized Calcium in Blood of Domestic Fowl: Dependence on Ovulatory Cycle In the present study the plasma concentration of both ionized and total calcium in arterial as well as in venous blood of Leghorn hens and its dependence on the ovulatory cycle were investigated. During the ovulatory cycle, the concentration of ionized calcium in blood of hens follows the course of a sine curve. Maximum calcium ion concentrations (1.58 mmol/l in venous blood and 1.48 mmol/l in arterial blood, respectively) were observed 3 to 6 hours after oviposition, and minimum concentrations (1.26 and 1.19 mmol/l, respectively) at 18 to 21 hours after oviposition. Changes in total and ionized calcium concentration went parallel. Six to 9 hours after oviposition maximum values (4.24 and 4.15 mmol/l respectively) and 21 to 24 hours after oviposition minimum values (3.25 and 2.99 mmol/l, respectively) were measured. The arterio-venous difference was −0.22 mmol/l on average. Zusammenfassung In der vorliegenden Arbeit wurde das Verhalten des ionisierten Calciums und das Gesamtcalciums im arteriellen und venosen Blut des Haushuhns (Leghorn) in Abhangigkeit vom Legezyklus untersucht. Die Konzentration des ionisierten Calciums im Blut der Hennen folgte wahrend des Legezyklus dem Verlauf einer Sinuskurve. Maxima (1,58 mmol/l im venosen bzw. 1,48 mmol/l im arteriellen Blut) wurden 3–6 Stunden nach der Eiablage und Minima (1,26 bzw. 1,19 mmol/l) 18–21 Stunden nach der Eiablage beobachtet. Der Gesamtcalciumspiegel veranderte sich etwa parallel zu der Konzentration des ionisierten Calciums. 6–9 Stunden nach der Eiablage erreichte er die hochsten Werte (4,24 bzw. 4,15 mmol/l) und 21–24 Stunden nach der Eiablage die niedrigsten (3,25 bzw. 2,99 mmol/l). Die arteriovenose Differenz betrug durchschnittlich −0,22 mmol/l.

The clinical efficiency of Mastodinon (Bionorica) is studied in management of 33 patients (average age 34,6 years) with different menstrual disfunctions and dysmenorrhea. In 13 patients these disturbances coexisted with hyperprolactinemia. As a result of 3-month treatment with Mastodinon we noted the normalization of menstrual function in 13 of 17 patients, and the decrease in prolactin serum levels on 10 of 13 women. The prolactin decrease was followed by increase in luteinizing hormone and progesteron, as chosen for ovulatory cycle. It is found that Mastodinon has the properties of dopaminomimetics and can be concerned as the alternative for synthetic dopaminergic drug therapy (Bromocriptine etc.).

Plasma progesterone and luteinizing hormone (LH) profiles were obtained during the first ovulatory cycle of heat-stressed (HS, 35 C; n = 24) and unstressed (US, 17 to 27 C; n = 24) hens using 30-min sampling intervals beginning approximately 6 h prior to ovulation. Progesterone levels from HS hens were lower from 6 h [.07 +/- .01 (SE) versus 1.66 +/- .25 ng/mL; P = .008] to predicted ovulation (.06 +/- .006 versus .70 +/- .18 ng/mL; P = .07). Likewise, LH levels from HS hens were lower from 6 h (1.55 +/- .16 versus 3.86 +/- .34 ng/mL; P = .007) to predicted ovulation (1.63 +/- .18 versus 2.50 +/- .27 ng/mL; P = .01). Eggs from HS hens were more often laid early (less than 24 h) than eggs from US hens (71.42 versus 13.33%, respectively; P = .01), but US hens more often laid eggs of a normal oviposition interval length (24 to 26 h) compared with HS hens (73.34 versus 14.29%; P = .0005). The percentage of delayed eggs (greater than 26 h) was not different (US, 14.29 versus HS, 13.37%; P = .75) between the two treatment groups. Basal production of progesterone by dispersed granulosa cells from US hens was 97.62 +/- 16.01 ng/mL. Challenge by LH increased this to 417.50 +/- 53.38 ng/mL (P = .0001). In contrast, basal progesterone secretion by cells from HS hens was 40.25 +/- 6.60 ng/mL (P = .0001) and LH challenge failed to increase progesterone production.(ABSTRACT TRUNCATED AT 250 WORDS)

Background: Studies on nickel patch test reactivity and reproducibility of positive tests at different points of the menstrual cycle are heterogeneous. Objective: To investigate if non-reproducibilities of positive nickel sulphate patch tests in the two different phases of ovulatory menstrual cycles with the endocrine evidence of luteal phase adequacy are statistically different. Methods: 15 women (group 1) with positive Finn chamber® nickel patch test results in the follicular phase of the ovulatory cycle and 13 women (group 2) with positive Finn chamber nickel patch test results in the luteal phase of the ovulatory cycle were tested again in the counter-phases of their ovulatory cycle, with a scheduled interval of 6 weeks following the first tests. Reproducibilities of the tests in the two groups were evaluated statistically. Results: 3 of the positive test results in group 1 (20%) and 2 of the positive test results in group 2 (15.4%) were non-reproducible. The difference was not statistically significant. Conclusion: The reproducibility of positive Finn chamber nickel patch tests does not seem to be affected by the changes in the follicular and luteal phases of the ovulatory cycle.

Objectives To measure the serum concentrations of lamotrigine throughout a complete menstrual cycle. Methods Serum concentrations of lamotrigine, estradiol, and progestogen throughout a menstrual cycle were measured in 2 young women not using hormonal contraception. Results and conclusions The physiological hormonal fluctuations during an ovulatory cycle were not associated with clinically relevant changes in lamotrigine serum concentrations.

The relationship between basal body temperature and circulating progesterone levels were investigated in a female beluga. Body temperature and serum concentrations of progesterone were measured daily and at 2-4 week intervals respectively, in a female beluga that was in captivity for 7 years between 1996 and 2003. The beluga first ovulated in April, 2000 (13 years old). Thereafter, serum concentrations of progesterone showed cyclic changes, indicating that the ovulatory cycle had started. Serum concentrations of progesterone ranged from 0.1 ng/ml to 15.7 ng/ml. Body temperature also showed cyclic changes during the estrous cycle. Body temperature ranged from 34.9 to 35.9 C, and tended to reach the peak during the high progesterone phase. Mating behavior was observed during the low body temperature phase. The changes in body temperature positively correlated with the circulating progesterone levels. The length of the estrous cycle was 36.7 +/- 3.9 (mean +/- SEM) days based on the intervals between the days of mating behavior. This is the first report demonstrating that body temperature clearly changes during the estrous cycle in a captive female beluga. The present finding suggests that measurement of body temperature is a useful method for detecting the ovarian cycle of the beluga in captivity.

We studied the activity levels of matrix metalloproteinase 1, 2, and 9 in periovulatory fluids from naturally occurring menstrual cycles versus those from samples taken from menstrual cycles stimulated with clomiphene citrate or recombinant stimulating hormone. No statistically significant differences were found.

1. The mathematical model of the hen's ovulatory cycle proposed by Etches and Schoch (British Poultry Science, 25: 65-76, 1984) predicts ovulation times for sequences of 2 to 9 ovulations only. 2. Continuous functions have been produced, representing the changes required to the parameters lambda1, lambda2, S1, S2, b1, b2 and b3, such that the prediction of any sequence length is now possible. 3. This improved ovulation model is capable of predicting ovulation times and intra-sequence ovulation intervals for any ovulation rate between 0.5 and 1.0. 4. The improved ovulatory model lends itself to stochasticity. The rate of lay of a population of hens at a time may be modelled with the use of means and standard errors for each of the parameters in the model. 5. Age-related changes in the ovulation rate of the population may be predicted using a combination of three methods, which are consistent with published theories that account for the decline in performance with time.

We studied the relationship between progesterone (P4) concentrations early in the estrus cycle and follicular dynamics in dairy goats. We used seven untreated goats (control group) and six progesterone treated goats (P group) with a controlled internal drug release device from Days 0 to 5 (Day 0: day of ovulation). We performed daily ultrasonograph during the interovulatory interval to determine ovarian change and took daily blood samples to determine serum estradiol 17beta (E2) and P4 concentrations by RIA. We divided the control goats into 3- (n = 4) and 4-wave goats (n = 3), according to the number of follicular waves recorded during the ovulatory cycle. Mean progesterone concentrations between Days I and 5 were higher and mean estradiol concentrations between Days 3 and 5 were lower in 4-wave goats (P4: 3.8+/-0.2 ng/ml; E2: 1.6+/-0.2 pg/ml) than in 3-wave goats (P4: 2.0+/-0.5 ng/ml, P < 0.05; E2: 4.4+/-0.9 pg/ml, P < 0.05). Wave 2 emerged earlier in 4-wave (Day 4.2+/-0.3) than in 3-wave goats (Day 7.3+/-0.3, P < 0.05). Three out of six of the progesterone-treated goats had short cycles (mean 8.0+/-0.0 days) and ovulated from Wave 1. The other three goats had shorter cycles (mean 18.3+/-0.3 days) than the control group (20.0+/-0.2 days; P < 0.05), although they were within the normal range of control cycles (shortened cycles). In the three treated goats with shortened cycles (two with four waves, one with three waves), mean progesterone concentrations between Days I and 5 were higher (4.7+/-0.6 ng/ml) than in the 3-wave control goats. In these goats, Wave 2 emerged at Day 4.3+/-0.3, similar to the time observed in 4-wave goats but earlier (P < or = 0.05) than in 3-wave control goats. Overall results confirm a relationship between the progesterone levels and the follicular wave turnover during the early luteal phase in the goat. Higher progesterone concentrations may accelerate follicular turnover probably by an early decline of the negative feedback action of the largest follicle of Wave 1. This is followed by an early emergence of Wave 2.

The effect of exogenous progesterone exposure early in the oestrous cycle on the duration of the interovulatory interval was studied in dairy goats. A controlled intravaginal drug release (CIDR-G) device was inserted for 5 days starting at day 0 (D0 group, n = 6) or day 3 (D3 group, n = 5) postovulation. A third group was composed of untreated control goats (control group, n = 7). Daily transrectal ultrasound was carried out during the interovulatory interval to assess the ovarian dynamics. Oestrous behaviour was checked twice a day and serum progesterone levels were assayed in daily jugular blood samples. Treated goats showed two different responses. In three D0 goats and one D3 goat, progesterone concentrations fell immediately after CIDR withdrawal and this was followed by oestrus and ovulation between days 8 and 11 (short cycles). In the other three D0 goats and in four D3 goats the treatment significantly reduced the interovulatory interval (18 .3 ± 0.3 and 18.5 ± 0.3 days, respectively) (shortened cycles) compared with the control group (20.0 ± 0.2 days; P< 0.05), but the intervals with progesterone concentrations over 1 ng/ml were not different (15.7 ± 0.3, 15.8 ± 0.7 and 16.0 ± 0.5 days for D0, D3 and control goats, respectively). In all D0 goats with a short cycle response, the ovulatory follicle arose from the first follicular wave but in the D3 goat with a short cycle it arose from the second follicular wave. These results showed that premature progesterone exposure early in the ovulatory cycle of the goat affected its length inducing short or shortened cycles. The effect of progesterone could either affect luteotropic support of the corpus luteum (CL) and/or stimulate a premature release of the luteolysin. © 2001 Elsevier Science B.V. All rights reserved.