Search

Adenomyosis of the uterus is characterized by the presence of islands of endometrial glands and stroma within the myometrium. Etiopathology of adenomyosis has not been clearly defined but it potentially interferes reproductive processes in cattle. The aim of this initial study was to evaluate the impact of age on the frequency of adenomyosis in cows. Endometrial tissues collected from cows slaughtered between Day 8 and 12 of the estrous cycle (N = 72) were divided into two age groups: (1) 2 to 4 years old (N = 36) and (2) 5 years old and older (N = 36). The tissues were stained with hematoxylin and eosin. The adenomyosis histopathomorphologic stage was classified on a four-point scale according to the penetration of endometrial structures inside the perimetrium. The protein expression of the 17-β estradiol (E2) and progesterone (P4) receptors were evaluated in the endometrial tissue samples by immunohistochemistry and Western blot analysis, and E2 and P4 concentrations were measured in the peripheral blood and uterine tissue. Adenomyosis was observed in 38 of the cows examined including 13 of the 2- to 4-year-old cows and 25 of the cows 5 years old or older. The frequency and intensity of adenomyosis increased with age. Higher E2 receptor protein expression was observed in adenomyotic cows and increased with disease development and increase of number of glands inside the uterus in the direction of perimetrium, and P4 receptor protein expression were unchanged in healthy and adenomyotic cows. An increase in the expression of E2 receptors and high, supraphysiological levels of E2 was detected in cows with III and IV degree of adenomyosis (P < 0.05). Overexpression of E2 receptor and alternations in E2 secretion might make the bovine uterus susceptible to a growth advantage of adenomyotic tissue over the surrounding myometrium. The pathogenesis and immunoendocrine mechanisms controlling adenomyosis in cattle warrant further study., (Published by Elsevier Inc.)

The aim of this study was to investigate the plasma concentrations of folic acid, vitamin B12 and progesterone at different stages of the sexual cycle and pregnancy, during induced abortion and in bitches with pyometra. Bitches (n = 97) were assigned to groups as follows: a) oestrous cycle (n = 42) b) pregnancy (n = 25) c) induction of abortion (n = 10 and d) pyometra (n = 20). Oestrous cycle stages were determined by vaginal inspection and cytology. Pregnancies were estimated by ultrasound (5.0 Mhz; linear transducer; Schimadzu) at days 15-25, 35-45 and 46-63 of pregnancy. Treatments for the induction of abortion were started between days 25 and 35 after mating (5 microg/kg cabergoline daily, Galastop; 5-10 microg/kg Alfaprostol every other day, Gabbrostim). Diagnosis of pyometra was confirmed by ultrasound and vaginoscopy. Folic acid and vitamin B12 concentrations did not differ among different stages of the oestrous cycle. The mean concentration of folic acid during early pregnancy (days 15-25) exceeded levels of later stages (days 46-63): 9.4 +/- 3.7 microg/ml and 4.7 +/- 1.8 microg/ml, respectively (p < 0.01). A positive correlation between folic acid and vitamin B12 was determined in pregnant dogs ( r = 0.925; p < 0.02). Before the induction of abortion, the concentration of folic acid was 9.6 +/- 5.2 microg/ml; during abortion it decreased to 5.0 +/- 3.2 microg/ml (p < 0.01). A significant correlation (r = 0.925; p < 0.02) between progesterone and folic acid was obtained in bitches with abortion. The mean concentration of folic acid in bitches with pyometra significantly differed from that of bitches at different stages of the oestrous cycle (p < 0.05). The mean concentration of folic acid was significantly lower in metoestrous bitches when compared to bitches with pyometra (p < 0.05). The decrease of serum concentrations of folic acid during pregnancy and induced abortion show that fetal growth and abortion caused higher consumption of folic acid. Concerning bitches did not show any deficiency symptoms, which is why it can be concluded that this decrease is physiological.

Bacterial products are thought to induce labor by stimulating the production of pro-inflammatory cytokines and prostaglandins in gestational tissues, leading to the onset of preterm parturition. Progesterone withdrawal is a prerequisite of parturition in many species. Yet a role for progesterone in the mechanisms responsible for preterm parturition, in the setting of infection, is unclear. The current studies were conducted to determine if a fall in serum progesterone concentrations occurs before the onset of bacterial product-induced preterm parturition in animals. Accordingly, pregnant mice at day 15 (70% gestation) were injected i.p. with Escherichia coli lipopolysaccharide (LPS; 50 microg/mouse) and timed-pregnant rabbits were inoculated transcervically with a suspension of E. coli to cause an ascending intrauterine infection. Control animals in both groups received equal volumes of sterile phosphate-buffered saline (PBS) solution. Blood specimens were collected at regular intervals and serum progesterone levels were determined by RIA. Within 14 h of LPS administration, mice delivered their pups. The median concentrations of serum progesterone were significantly lower at 1 h, 4 h, 10 h, and at the onset of preterm parturition (11-12 h) after LPS injection, compared to that in animals given PBS. Similarly, E. coli-inoculated rabbits delivered 1-2 days posttranscervical inoculation and demonstrated 60% decrease in serum progesterone within 12-24 h of inoculation compared to those given PBS. Parturition in both control groups occurred at term, following typical progesterone withdrawal. It is concluded that LPS administration to pregnant mice and ascending intrauterine infection in pregnant rabbits is associated with a dramatic fall in serum progesterone concentrations prior to the onset of parturition.

The pathogenic significance of progesterone in pyometra in bitches was investigated by evaluating the stages of the oestrous cycles of 369 bitches with pyometra. Concentrations of progesterone and oestradiol were determined in 100 bitches with pyometra before ovariohysterectomy. Six bitches with pyometra with progesterone > 5 ng ml-1 and oestradiol < 25 pg ml-1 were treated with the antigestagen RU 46534 (6 mg kg-1, s.c.) twice on day 1 and once on days 2, 3 and 4; ovariohysterectomy was performed on day 6. Six control bitches that met the same criteria were ovariohysterectomized and uterine morphology was compared with that of the treated bitches. The effects of treatment were monitored by hormone, ultrasonographic imaging and histomorphological studies. The results confirm that pyometra may occur at any stage of the reproductive cycle and that most animals are in the phase of dioestrus. Uterine mass (g kg-1 bodymass) with versus without content was not different in treated bitches and was significantly lower (P < 0.01) than in the control bitches. In all six dogs general clinical conditions improved during the observation period; 23.5 +/- 11.1 h after the start of antiprogestin treatment a profuse, purulent vulval discharge was observed. The effusion was nearly complete at day 6. The maximal detectable uterine lumen varied between 23 and 39 mm in diameter, it was no longer detectable on day 6. Oestradiol concentrations remained constant while progesterone decreased with distinct individual variations. Morphometrical examination of the endometrium revealed no differences between groups. The data suggest that antigestagen treatment is a promising approach for treatment of pyometra in bitches.

In the present study, 35 bitches (various breeds and ages) with pyometra were involved. Blood sampling (jugular vein) took place every day between examination and hysterectomy. All the bitches examined after 60 days post-oestrus had a low progesterone concentration (about 1 ng/ml). Along the 27 bitches observed before that time, 22 had a high mean level (about 8 ng/ml). By contrast 5 of them had low levels. As a whole these results suggest that: 1) There is no evidence of an essentially high or prolonged progesterone secretion in pyometra. 2) Luteolysis occuring normally about 60 days post ovulation is not postponed by this affection and 3) In some animals, early luteolysis seems to occur. Therefore it cannot be concluded that progesterone has an indispensalbe role in polymetra.

Sixty Holstein cows were allocated to three groups. Twenty cows had retained placenta. The remaining cows were examined on d 14 postpartum and those with purulent discharges (n = 22) were assigned to one group and the remaining (n = 18) to a control group. Within each group, cows were given randomly either gonadotropin-releasing hormone (i.m., 200 micrograms) or saline on d 15 postpartum to evaluate the effect on changes in ovarian structures and plasma progesterone through 50 d postpartum and fertility. Corpora lutea were found in control cows by d 21, cows with uterine discharge by d 28, and cows with retained placenta by d 27. Maximum progesterone production during the first luteal phase was higher in control cows than in cows with purulent discharge or retained placenta (4.66 ng/ml compared with 3.23 and 3.34 ng/ml, respectively). Duration of the first corpus luteum was affected by clinical condition. Only 6.2% of cows with retained placenta had corpora lutea of normal duration (12 to 16 d), whereas 43.8 and 50.0% of cows with uterine discharge and control cows had normal postpartum luteal phases. Measures of fertility were not affected by gonadotropin-releasing hormone. Control cows had less days to conception (97) and fewer services per conception (1.6) than cows with retained placenta (134 and 2.5, respectively). Clinical group affected reproduction more than gonadotropin-releasing hormone did, possibly by altering ovarian function.