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Objective: This study was undertaken to investigate the effects of 17beta-estradiol (E2) on G1 cell cycle progression and proliferation in uterine fibroid and myometrial cells and the roles of phosphatidylinositol-3 kinase and mammalian target of rapamycin in mediating these estrogen effects., Study Design: The human uterine smooth muscle-derived cells (UtSM) and uterine leiomyoma-derived cells (UtLM) were treated with varying doses of E2 with or without pretreatment with LY294002, a phosphatidylinositol-3 kinase inhibitor, or rapamycin, a mammalian target of rapamycin inhibitor. The effects of E2 on cell cycle progression and proliferation and the roles of phosphatidylinositol-3 kinase and mammalian target of rapamycin in E2-induced effects were studied., Results: Compared with controls, E2 significantly induced G1 cell cycle progression and proliferation in uterine smooth muscle-derived cells and uterine leiomyoma-derived cells. These effects, however, were significantly blocked when LY294002 or rapamycin was used., Conclusion: E2 significantly induces G1 cell cycle progression and cell proliferation in uterine smooth muscle-derived cells and uterine leiomyoma-derived cells, in which phosphatidylinositol-3 kinase and mammalian target of rapamycin are essentially required.

Objective: The purpose of this study was to compare acetaminophen with ibuprofen for pain relief and menstrual fluid prostaglandin F2alpha (PGF2alpha) suppression in primary dysmenorrhea., Study Design: Twelve subjects were randomized to placebo, acetaminophen (1000 mg orally, 4 x daily for 3 days) or ibuprofen (400 mg orally, 4 x daily for 3 days), once during each cycle in a prospective, double-blinded, crossover study. Using preweighed super absorbent tampons, menstrual fluid was collected, extracted, and PGF2alpha radioimmunoassayed., Results: Ten patients completed the study. Ibuprofen (P = .002) and acetaminophen (P = .022) were rated significantly better than placebo. Total menstrual fluid PGF2alpha with placebo was 36.2 + 6.1 microg but were 14.8 + 3.0 microg with ibuprofen (P = .001) and 21.4 + 3.4 microg with acetaminophen (P = .008). PGF2alpha concentrations with placebo were 0.34 + 0.054 microg/mL, with ibuprofen 0.16 + 0.026 microg/mL (P = .001), and with acetaminophen 0.23 + 0.029 microg/mL (P = .016)., Conclusion: Both ibuprofen and acetaminophen were superior to placebo for pain relief and menstrual fluid PGF2alpha suppression, with ibuprofen being more potent.

Objectives: This study was undertaken to determine expression levels of oxytocin receptor and its gene in peri-implantation phase human endometrium during clomiphene-treated cycles compared with control cycles., Study Design: Oxytocin receptor and its messenger ribonucleic acid in peri-implantation phase endometrium during control and clomiphene-treated (50 mg days 5 to 9) cycles of 5 healthy fertile women were determined by immunohistochemical methods, Western blot analysis with monoclonal antibody against amino acids 20 through 40 of the extracellular N-terminal human oxytocin receptor, and reverse transcription-polymerase chain reaction with oligonucleotide primers to amplify the 391-base pair fragment of the oxytocin receptor gene., Results: Oxytocin receptor and its messenger ribonucleic acid were expressed in human peri-implantation phase endometrial samples from both control and clomiphene-treated cycles. The receptor was localized predominantly in the epithelial cells and glands, with little or none detected in the stroma. Oxytocin receptor protein was separated out as a single 70-kd band by Western blot analysis; its relative abundance was significantly reduced during clomiphene-treated cycles. The messenger ribonucleic acid was detected in all endometrium during control and clomiphene-treated cycles, with greater expression during control cycles., Conclusions: The expressions of oxytocin receptor and its gene in luteal phase human endometrium suggest a functional relevance in modulation of biochemical changes for implantation.

Objective: The study determined the expression of oxytocin receptor and its gene in human uterine leiomyoma compared with the adjacent myometrium., Study Design: Paired samples of leiomyoma and the adjacent myometrium from 20 women through the menstrual cycle, menopause, and various hormone treatments were studied. Oxytocin receptor was immunohistochemically localized with use of the specific antibody (2F8) to human oxytocin receptor. Oxytocin receptor protein was determined by Western blotting, whereas reverse transcription-polymerase chain reaction was used for oxytocin receptor messenger ribonucleic acid expression., Results: Immunohistochemistry showed positive staining in all tissues examined, relatively more intense in the myometrium than in the adjacent leiomyoma, and in tissues from the preovulatory than the postovulatory phase. Western blotting showed a single 70-kd band corresponding to the oxytocin receptor. The relative abundance of oxytocin receptor in both leiomyoma and myometrium was significantly higher during the preovulatory (n = 5) than the postovulatory (n = 5) phase (P = .034 and .05). In women receiving gonadotropin-releasing hormone agonist (n = 1) or oral contraceptives (n = 1), after the menopause (n = 2), and with irregular vaginal bleeding (n = 1), oxytocin receptor levels in leiomyoma and myometrium were unchanged but were reduced in anovulatory cycles (amenorrhea, n = 2). Reverse transcription-polymerase chain reaction showed messenger ribonucleic acid for oxytocin receptor as a 391-bp band in all leiomyomas and myometrium examined., Conclusions: Leiomyoma and myometrium express the gene and protein for oxytocin receptor, which is probably partially regulated by ovarian sex steroids during the menstrual cycle.

Objective: The purpose of this investigation was to determine whether treatment with clomiphene citrate, which is estrogenic and antiestrogenic, affects the expression of the cell adhesion molecule E-cadherin in human periimplantation phase endometrium., Study Design: Five healthy women were studied for two cycles each, a control and a treated (clomiphene 50 mg daily, days 5 through 9) cycle. A biopsy specimen of endometrial tissue was studied (8 to 10 days post luteinizing hormone surge) for immunohistochemical localization, Western analysis of E-cadherin with use of a highly specific monoclonal antibody to human E-cadherin, and determination of messenger ribonucleic acid for E-cadherin by reverse transcription-polymerase chain reaction by use of oligonucleotide primers specific to E-cadherin and amplifying a 432 bp fragment., Results: Luteal phase plasma progesterone levels were significantly higher in clomiphene cycles. E-cadherin was immunocytochemically present in endometrium of control and treated cycles with no apparent difference in staining intensity. Western blots revealed the presence of E-cadherin. It was relatively more abundant in clomiphene-treated than control cycles but not significantly different. The message for E-cadherin gene is expressed in endometrium of control (n = 5) and clomiphene cycles (n = 4)., Conclusions: E-cadherin and its gene transcripts are expressed in periimplantation phase endometrium and are not significantly affected by clomiphene treatment.

The purpose of this study was to compare the CUE method for family planning with the Ovulation Detection Method for defining the fertile phase of the menstrual cycle. We evaluated 42 cycles from 10 women in Monterrey, Mexico, who were monitored by basal body temperatures, urinary LH, pelvic ultrasound, and the CUE monitor. The fertile phase of the cycle was adequately defined in all cycles using the CUE method, and in 35 cycles (83.3%) by the Ovulation Method. Using our protocol, the period of recommended abstinence with the CUE method is 9 days and with the Ovulation Method 11 days. The CUE method accurately defines the fertile phase of the menstrual cycle, thus improving the predictability of ovulation for women who use natural methods of birth control.

Objective: Our purpose was to determine and compare the efficacy and hormonal and metabolic effects of 1.25 mg with 2.5 mg of gestrinone given twice a week in the treatment of mild and moderate pelvic endometriosis., Study Design: A phase II, prospective, randomized, double-blind study involving 11 patients given gestrinone 1.25 mg (five patients) or 2.5 mg (six patients) orally twice a week for 24 weeks was performed. Revised American Fertility Society scores were determined by laparoscopy before and at the end of treatment. Serum hormone (free thyroxine, free testosterone, estradiol, progesterone, follicle-stimulating hormone, luteinizing hormone), sex hormone binding globulin, and lipid concentrations were measured before, throughout, and for 6 months after treatment. Quantitated computerized tomography of thoracic 12 through lumbar 4 vertebral bodies were determined before, at the end of, and 6 months after treatment., Results: Gestrinone 2.5 mg significantly reduced the endometriosis implant score from 10.3 +/- 2.8 to 3.8 +/- 0.8 (p = 0.05). Both doses significantly reduced serum progesterone and sex hormone binding globulin levels. Estradiol, free testosterone, free thyroxine, follicle-stimulating hormone, and luteinizing hormone levels were not significantly affected. Spinal bone increased significantly by 7.1% with 2.5 mg but lost significantly by 7.1% with 1.25 mg gestrinone; these changes had not reversed completely 6 months after stopping treatment., Conclusions: In mild to moderate pelvic endometriosis 2.5 mg of gestrinone twice a week was more effective and had a more positive effect on bone mass than did 1.25 mg of gestrinone.

Midluteal phase endometrium was histologically dated with midcycle luteinizing hormone surge time in 29 cycles from 10 parous women during untreated cycles (control) and treatment with clomiphene citrate 50 mg and 150 mg daily on days 5 through 9. Integrated progesterone output for 7 days after luteinizing hormone surge calculated from the daily plasma progesterone levels was 66.6 +/- 9.8 ng/ml in the control group compared with 117.5 +/- 18.6 ng/ml for clomiphene citrate 50 mg treatment and 152.1 +/- 11 ng/ml for clomiphene citrate 150 mg treatment (p less than or equal to 0.05). Only one cycle (clomiphene citrate 150 mg) had an out-of-phase endometrium and a significantly reduced integrated progesterone output of 28 ng/ml. All other cycles showed synchronous endometrial maturation. We conclude that luteal insufficiency as a result of clomiphene citrate treatment in ovulatory women is infrequent and is more likely to be a result of functional outcome of a relative lack of luteal phase progesterone output.

Plasma and salivary progesterone and estradiol were measured throughout nine menstrual cycles and before and after intramuscular injection of progesterone in four women. Mean +/- standard error of the mean (SE) salivary progesterone increased significantly from 238.7 +/- 14.3 pg/ml in the proliferative phase to 475.3 +/- 39.8 pg/ml in the secretory phase (p less than 0.001). There was a highly significant correlation between plasma and salivary progesterone levels throughout the menstrual cycle (r = 0.5841, p = 0.001). The ratio of plasma to salivary progesterone was 6.4 during the proliferative phase and increased to 26.7 during the secretory phase. Free unbound progesterone as determined by equilibrium dialysis gave a mean +/- SE level of 126.8 +/- 6.9 pg/ml during the proliferative phase and increased significantly to 196.8 +/- 18.8 pg/ml during the secretory phase (p less than 0.001). The corresponding levels in the plasma were 88.5 +/- 11.2 pg/ml, which increased significantly to 332.2 +/- 39.2 pg/ml (p less than 0.001). Free progesterone constituted 53.7% and 41.4% of salivary progesterone during the proliferative and secretory phases, respectively, whereas the corresponding percentages in the plasma were 5.8% and 2.6%. Both plasma and salivary progesterone levels increased in a dose-dependent manner after an intramuscular injection of progesterone, with peak levels being attained from 2 to 3 hours after the injection. Salivary estradiol levels were 5 to 18 and 8 to 35 pg/ml in the proliferative and secretory phases, respectively, but showed no correlation with plasma estradiol levels. The findings are discussed in relationship to the origin of salivary progesterone and the potential use of it as an index of ovulation.

Naloxone (10 mg) was given intravenously to seven postmenopausal women not receiving hormone treatment and to six postmenopausal women receiving Premarin-Provera treatment during the Premarin phase and also during the Premarin-Provera phase of therapy. Baseline estrone and estradiol levels (mean +/- SEM) were significantly lower in the group not receiving hormones (46.0 +/- 5.2 pg/ml and 28.4 +/- 3.1 pg/ml, respectively) than in the group in the Premarin phase of therapy (154 +/- 14 pg/ml and 79 +/- 13 pg/ml) and the group in the Premarin-Provera phase (135.1 +/- 8.3 pg/ml and 57.5 +/- 3.0 pg/ml) (p less than 0.005). Follicle-stimulating hormone, luteinizing hormone, and prolactin levels were 118.7 +/- 5.3 mIU/ml, 118.7 +/- 9.5 mIU/ml, and 9.2 +/- 0.7 ng/ml, respectively, with no significant change after naloxone administration in untreated women. With hormone therapy the basal follicle-stimulating hormone and luteinizing hormone levels decreased significantly while basal plasma estrone and estradiol increased significantly. In both the group in the Premarin phase of therapy and the group in the Premarin-Provera phase, luteinizing hormone levels increased significantly at 30 (135% +/- 10%, 144% +/- 8%), 45 (150% +/- 12%, 133% +/- 11%), 60 (149% +/- 15%, 128% +/- 11%), and 90 (139% +/- 15%, 132% +/- 13%) minutes after naloxone administration (p less than 0.01 to p less than 0.001). Follicle-stimulating hormone levels did not change significantly whereas prolactin levels showed a trend toward a decrease. These findings indicate that opioid inhibition of gonadotropins is reduced in postmenopausal women but increased with Premarin-Provera treatment. The effect of sex steroid on the opioid system in the postmenopausal women differs from that in the premenopausal women.

To determine the temporal relationship of the endocrine events involved in rabbit blastocyst implantation, (1) progesterone (P) and estradiol (E) in plasma and uterine flushings, (2) P and E in the cytosol of endometrium and myometrium, and (3) P receptors (PR) and E receptors (ER) in endometrium and myometrium were examined from days 0 through 7 post coitum by radioimmunoassay and radioreceptorassay. Plasma P levels increased significantly from 0.3 +/- 0.06 to 76 +/- 9.4 ng/ml (p = less than 0.005) 2 hours after mating (day 0), declined to 10.0 +/- 1.2 ng/ml by day 6, and increased to 12.0 +/- 1.2 ng/ml by day 7. Cytosol P levels of endometrium and myometrium increased from 3.2 +/- 0.2 to 22.8 +/- 2.2 ng/gm and 2.1 +/- 0.4 to 14.1 +/- 2.1, respectively, from days 1 to 6. On day 7, cytosol P levels of the embryonic segment (8.2 +/- 0.5 ng/gm) were lower than those of the interembryonic segment (12.4 +/- 1.8 ng/gm). P levels in uterine flushings increased significantly from 0.05 +/- 0.01 ng/ml on day 0 to 19.9 +/- 0.7 ng/ml on day 7 (p = less than 0.001). In contrast, E levels in plasma, uterine flushings, and cytosol of uterine tissues showed no significant change from days 1 through 7, but the levels from 6 hours after mating were significantly higher than those before mating (p = less than 0.05). ER in the cytosol and nucleus of all uterine regions increased significantly after mating but decreased after implantation. In contrast, PR in the cytosol and nucleus of all uterine regions showed no significant change on days 0 to 6 post coitum. After implantation, the embryonic segment had significantly higher PR in the nucleus than that in the cytosol (13.0 +/- 1.5 versus 8.0 +/- 0.5 fmol/micrograms), whereas the interembryonic segment had significantly higher PR in the cytosol than that in the nucleus (12.0 +/- 0.5 versus 9.0 +/- 0.5 fmol/micrograms DNA). These findings showed that changes in P in the plasma and uterine flushings preceded those in uterine tissues before implantation. The changes in uterine tissue ER and PR after mating but before and after implantation suggest that the putative nidatory sites are prepared for implantation but undergo endocrine changes to protect the conceptus immediately after implantation.

Seventeen human fetal and neonatal pituitary glands were removed at necropsy, and analyzed for oxytocin content by a specific and sensitive radioimmunoassay, after homogenization in 0.4M acetic acid. Serial dilution of the pituitary extract showed parallelism with the oxytocin standard curve on the radioimmunoassay. Column chromatography of the pituitary gland extract gave a single peak of immunoreactive oxytocin as determined by the radioimmunoassay. In eight fetuses, 14 to 17 weeks' gestation, pituitary gland oxytocin was 10.2 +/- 5.9 ng/gland (mean +/- SE), whereas an 18-week fetus had 5.8 ng of oxytocin per gland. Pituitary gland oxytocin content increased to 38.4 ng/gland in a 20-week fetus removed at hysterectomy, and 31.6 ng/gland in a 26-week fetus. Fetal pituitary gland oxytocin values were 22.1 ng/gland and 57.0 ng/gland at 32 weeks and increased significantly to 544.3 +/- 33.8 ng/gland in 1- to 5-day-old term newborn infants (n = 3). However, a 13-day-old term newborn infant had 3.7 ng of oxytocin per pituitary gland. The increased pituitary gland oxytocin content with advancing gestation was due to a significant increase in oxytocin concentration rather than to an increase in the weight of the pituitary gland. The findings indicate that oxytocin is present in fetal pituitary glands as early as 14 to 17 weeks' gestation and increases at term to 50 and 13 to 14 times more than in early midtrimester and early third-trimester pregnancy, respectively.

To determine the effect of oral contraceptives on endogenous opioid modulation of the hypothalamic-pituitary axis, we gave a bolus dose of 10 mg of naloxone intravenously in women using Lo/Ovral-28 oral contraceptives and in normal (control) women during the follicular (days 8 to 9) and luteal (days 21 to 23) phases. Plasma follicle-stimulating hormone, luteinizing hormone, and prolactin were measured by radioimmunoassay before and after naloxone at regular intervals. In oral contraceptive users (n = 5) basal plasma follicle-stimulating hormone (3.7 +/- 0.4 mIU/ml) and luteinizing hormone (3.2 +/- 0.5 mIU/ml) levels were significantly lower than in control subjects during both follicular (10.7 +/- 0.9 and 16.7 +/- 2.0) and luteal (7.7 +/- 1.4 and 10.0 +/- 0.9, respectively) phases (p less than 0.05 to 0.001). In contrast the basal plasma prolactin level was significantly higher in oral contraceptive users (25.0 +/- 4.1 ng/ml) than in control subjects during the follicular (11.8 +/- 1.2) and luteal (11.0 +/- 0.8) phases (p less than 0.01). In control subjects, follicle-stimulating hormone, luteinizing hormone, and prolactin levels did not change significantly after naloxone in the follicular phase, but naloxone elicited a significant synchronous release of luteinizing hormone and prolactin during the luteal phase. In contrast, oral contraceptive users showed increases in luteinizing hormone and prolactin after naloxone that were not significantly different from the basal plasma levels.

Oxytocin concentrations were determined in baboon (Papio anubis) corpora lutea, and the effect of oxytocin on dispersed luteal cell progesterone production was evaluated. Oxytocin concentrations increased significantly from an early luteal phase value of 2.1 +/- 1.1 ng/gm to a peak concentration of 18.1 +/- 4.3 ng/gm wet weight in midluteal phase corpora lutea. Corpora albicantia and ovarian stroma had comparatively low oxytocin concentrations. Reverse-phase high-pressure liquid chromatography of corpora lutea extracts gave a peptide peak (retention time, 17.25 min) similar to a standard oxytocin peak. Plasma oxytocin levels, which were significantly higher in the ovarian vein draining a corpus luteum than in the contralateral side or the femoral vein, declined significantly after luteectomy. Oxytocin was localized by immunocytochemical methods in luteal cells. In the early luteal phase oxytocin (4 to 800 mU; 1 mU is equivalent to 2 ng) inhibited basal and human chorionic gonadotropin-stimulated progesterone production by dispersed luteal cells, but in the late luteal phase 200 to 800 mU oxytocin inhibited only human chorionic gonadotropin-stimulated progesterone output. Oxytocin did not affect luteal cell progesterone production in the midluteal phase. Thus oxytocin is present in corpora lutea, can be localized in the luteal cells, is probably produced locally, and may modulate luteal cell progesterone production.

The effects of clomiphene citrate on endometrial nuclear estradiol receptors and progesterone receptors were examined in 10 normal women during an untreated cycle (control) and during treatment with 50 mg clomiphene citrate and 150 mg clomiphene citrate daily on days 5 through 9. Concentrations and binding constants of the receptors were determined in endometrium obtained 8 to 12 days after midcycle luteinizing hormone surge. Scatchard plots for both estrogen receptors and progesterone receptors were linear, indicating only one type of high-affinity binding sites. In control cycles, estrogen receptor levels (mean +/- SEM) were 199.6 +/- 23.1 fmol/mg deoxyribonucleic acid, (n = 8) and were not significantly different from either 50 mg clomiphene citrate (180.5 +/- 19.1 fmol/mg deoxyribonucleic acid, n = 6) or 150 mg clomiphene citrate (194.3 +/- 35.2 fmol/mg deoxyribonucleic acid, n = 4). Similarly, the dissociation constants were unaffected by clomiphene citrate treatment. The concentrations of progesterone receptors in the control cycles (613 +/- 31 fmol/mg deoxyribonucleic acid, n = 5) and treatment cycles (50 mg clomiphene citrate -652.8 +/- 121 fmol/mg deoxyribonucleic acid, n = 6; 150 mg clomiphene citrate -592.6 +/- 31 fmol/mg deoxyribonucleic acid, n = 7) were also not significantly different. Clomiphene citrate also did not affect dissociation constants for progesterone receptors. Therefore, ovulation induction with clomiphene citrate apparently did not affect peri-implantation phase endometrial estrogen receptors and progesterone receptors or their respective binding constants.

Determined by a sandwich, solid-phase radioimmunoassay with mouse monoclonal antibody, OC 125, plasma CA 125 levels were significantly elevated in stage III (mean +/- SEM = 32.7 +/- 5.2 U/ml, n = 17, p = less than 0.01) and stage IV endometriosis (37.2 +/- 10.5 U/ml, n = 6, p = less than 0.005) compared with levels during the follicular (15.9 +/- 1.5 U/ml, n = 12) and secretory phases (15.8 +/- 1.3 U/ml, n = 15) of control women and users of oral contraceptives (15.5 +/- 1.2 U/ml n = 10). However, CA 125 levels were not significantly elevated in women with stage I (16.6 +/- 2.0 U/ml, n = 28) or stage II endometriosis (17.9 +/- 2.1 U/ml, n = 13). Peritoneal fluid levels of CA 125 (n = 14) were significantly higher (2 to 9.3 times) than the corresponding paired plasma levels in participants with stage I, II, or III endometriosis. In patients treated with danazol (n = 10) or buserelin (n = 17), plasma CA 125 levels decreased significantly by midtherapy, remained suppressed at the end of therapy, but rebounded to near pretreatment levels 6 months after treatment was completed. With gestrinone therapy a similar decline was observed but became significant only at the end of therapy. Our findings indicate that elevated plasma CA 125 levels may prove useful in the management of endometriosis.

To determine the site of oxytocin in human ovaries and its relationship with ovarian steroids, oxytocin and steroid hormones were measured in ovarian tissues, ovarian vein, and peripheral blood. Corpus luteum had significantly higher oxytocin, estrone, estradiol, and progesterone concentrations than corpus albicans and ovarian stroma (p = less than 0.01 to less than 0.001). Oxytocin concentrations in corpus luteum correlated significantly with estrone, estradiol, and progesterone. Oxytocin in corpus luteum increased from 14.0 +/- 1.8 ng/gm of wet weight in early to 30.8 +/- 0.9 ng/gm in midluteal phases (p = less than 0.001). Reverse phase high pressure liquid chromatography showed similarity between oxytocin in corpus luteum and synthetic oxytocin. Ovarian vein draining corpus luteum had significantly higher plasma oxytocin (11.8 +/- 1.5 pg/ml) than those without corpus luteum (2.1 +/- 0.2 pg/ml) or in the peripheral blood (2.9 +/- 0.3 pg/ml) (p = less than 0.001). Oxytocin in corpus luteum correlated significantly with its ipsilateral ovarian vein level of oxytocin, estrone, progesterone, and 17 alpha-hydroxyprogesterone. Our findings demonstrate that oxytocin is present and probably produced in corpus luteum and secreted into its ovarian vein; it may regulate corpus luteum release of progesterone, 17 alpha-hydroxyprogesterone, and estrone.

To assess fetal oxytocin release in relation to maternal oxytocin, serial paired maternal (femoral artery) and fetal (aorta) plasma oxytocin were determined by a specific and sensitive radioimmunoassay during pregnancy and parturition in the sheep. The maternal oxytocin level was 29.1 +/- 2.6 pg/ml (mean +/- SE) but was significantly lower than fetal oxytocin levels of 45.8 +/- 4.3 pg/ml (p less than 0.001). There was a significant correlation between paired maternal oxytocin and fetal oxytocin levels throughout late pregnancy (r = 0.2523, p less than 0.05). Maternal oxytocin levels calculated for every 5 days' gestation ranged from 15.8 +/- 2.7 to 32.7 +/- 5.6 pg/ml while the corresponding fetal oxytocin levels (21.6 +/- 3.5 to 62.5 +/- 21.6 pg/ml) were always higher (92 to 135 days) but not significantly different. However, at 136 to 142 days' gestation, fetal oxytocin levels (63.9 +/- 14.1 pg/ml) were significantly higher than maternal oxytocin levels (20.1 +/- 3.3 pg/ml) (p less than 0.01). Based on observations in two animals, fetal oxytocin levels appeared higher than maternal oxytocin levels at parturition with an increase a few days before labor. Our findings indicate that, in the sheep, fetal oxytocin levels were usually higher than but not significantly different from maternal oxytocin levels and that fetal oxytocin levels changed in relation to labor, suggestive of fetal release of oxytocin.

The effect of estradiol, progesterone and norgestrel on serum insulin and glucose levels and on insulin binding to adipocytes, hepatocytes and diaphragm muscle cell membranes has been evaluated in castrated male rats. Estradiol administration (5 micrograms/day X 6) significantly increased basal plasma insulin levels and the amount of insulin bound to fat and liver cells as well as muscle cell membranes. Progesterone treatment (5 mg/day X 6) caused a slight increase of basal insulin levels and a decrease of insulin binding to fat cells. Norgestrel treatment (5 mg/day X 6) decreased both insulin levels and the amount of insulin bound to adipocytes; a much lower dose of norgestrel, 6 micrograms/day X 7, also caused a decline in adipocyte insulin binding due to an apparent increase in the dissociation constant of the high affinity binding sites. These studies demonstrate that ovarian sex steroids have a significant effect on insulin binding to target cells. This animal model would assist in determining the mechanisms involved in changes of carbohydrate metabolism which occur during the menstrual cycle, pregnancy, the menopausal state and with the use of oral contraceptives.

To determine the role of placental progesterone in the onset of labor, tissue progesterone concentrations and in vitro conversion of tritiated pregnenolone to progesterone were examined in the placentas, chorion, and amnion of 12 term pregnancies delivered by cesarean section with or without labor and vaginal delivery. In all instances, the placenta had significantly higher progesterone concentrations than the chorion or amnion. Progesterone concentrations in the chorion were significantly lower after the onset of labor than before. The placenta and chorion but not the amnion converted pregnenolone to progesterone; the placenta had a significantly greater conversion rate than the chorion in all instances. Placental conversion of pregnenolone to progesterone increased significantly after labor to reach a maximum with vaginal delivery. Chorionic conversion of pregnenolone to progesterone was significantly increased after vaginal delivery but was similar after cesarean section with or without labor. The reduced tissue progesterone in the chorion, together with enhanced placental and chorionic production of progesterone from its precursor, pregnenolone, suggest that rapid metabolism and increased binding of progesterone locally in the placenta and membranes may lead to the local withdrawal or decline of progesterone and onset of labor.

Estradiol and progesterone receptors in the myometrium, decidua, placenta, chorion, and amnion of eight women who underwent elective cesarean section at term were determined by means of an exchange assay. The hormone levels in the peripheral plasma and cytosol of these tissues were measured by radioimmunoassays. Maternal plasma and the placenta had high concentrations of estradiol and progesterone, with the placenta having 12 times more progesterone than in maternal plasma but only half the concentrations of estradiol in maternal plasma. The decidua and placenta had detectable levels of cytosol and nuclear estradiol receptors, but the myometrium had no measurable cytosol estradiol receptors, whereas the chorion and amnion had neither cytosol nor nuclear estradiol receptors. However, the chorion and amnion had significantly higher concentrations of estradiol in the cytosol than those in the decidua and myometrium. Only the decidua and myometrium had cytosol and nuclear progesterone receptors, but the placenta, amnion, and chorion had neither cytosol nor nuclear progesterone receptors. In contrast, progesterone hormone levels were significantly higher in the placenta, amnion, and chorion than in the decidua and myometrium. The findings indicate that, in the term pregnant uterus, (1) the placenta, amnion, and chorion are rich in progesterone, estradiol, and nuclear estradiol receptors but have no progesterone receptors, (2) the decidua and myometrium have nuclear estradiol and progesterone receptors, and (3) the myometrium has a higher progesterone/estradiol ratio than that of the peripheral plasma, thus suggesting a highly progesterone-dominated uterus.

Paired samples of blood and saliva from 37 men and nine women throughout the menstrual cycle were measured for testosterone by radioimmunoassay and free testosterone by equilibrium dialysis. There was a highly significant correlation between plasma and salivary testosterone, with a correlation coefficient r = 0.71 (p = less than 0.001). In men, free testosterone constituted 78% of salivary testosterone but only 4% of plasma testosterone; mean +/- SE salivary testosterone was 193.7 +/- 6.7 pg/ml compared to plasma testosterone of 5,140 +/- 298.0 pg/ml. Salivary testosterone decreased significantly from a morning (0800 hours) level of 208 +/- 7.5 to an evening (1800 hours) level of 174 +/- 8.4 pg/ml (p = less than 0.001) (n = 23). Similarly, plasma testosterone was significantly higher in the morning (6,584 +/- 472 pg/ml) than in the evening (5,571 +/- 357 pg/ml) (p = less than 0.005) (n = 25). Free testosterone in saliva and plasma also showed significantly higher morning than evening levels. The coefficients of variability for hourly changes (0900 to 1800 hours) in salivary testosterone and free testosterone were 13.6% and 16.7% compared to 12.7% and 20.9% for plasma testosterone and free testosterone, respectively. In women, salivary testosterone during the proliferative phase of the menstrual cycle was 108.3 +/- 5.8 pg/ml, and it increased significantly to 130.5 +/- 6.0 pg/ml in the secretory phase (p = less than 0.02). Our findings indicate that measurements of salivary testosterone reflect plasma testosterone and may be a useful noninvasive method of assessing levels of testosterone.

Epidermal growth factor receptors are present in many reproductive tissues but have not been demonstrated in the human corpus luteum. To determine the presence of epidermal growth factor receptors and its binding characteristics, we carried out studies on the plasma cell membrane fraction of seven human corpora lutea (days 16 to 25) of the menstrual cycle. Specific epidermal growth factor receptors were present in human corpus luteum. Insulin, nerve growth factor, and human chorionic gonadotropin did not competitively displace epidermal growth factor binding. The optimal conditions for corpus luteum-epidermal growth factor receptor binding were found to be incubation for 2 hours at 4 degrees C with 500 micrograms plasma membrane protein and 140 femtomol 125I-epidermal growth factor per incubate. The number (mean +/- SEM) of epidermal growth factor binding sites was 12.34 +/- 2.99 X 10(-19) mol/micrograms protein; the dissociation constant was 2.26 +/- 0.56 X 10(-9) mol/L; the association constant was 0.59 +/- 0.12 X 10(9) L/mol. In two regressing corpora lutea obtained on days 2 and 3 of the menstrual cycle, there was no detectable specific epidermal growth factor receptor binding activity. Similarly no epidermal growth factor receptor binding activity could be detected in ovarian stromal tissue. Our findings demonstrate that specific receptors for epidermal growth factor are present in the human corpus luteum. The physiologic significance of epidermal growth factor receptors in human corpus luteum is unknown, but epidermal growth factor may be involved in intragonadal regulation of luteal function.

Peritoneal fluid obtained at laparoscopy from 49 women was measured for its content of prostaglandin E2 (PGE2), prostaglandin F2 alpha (PGF2 alpha), 6-keto-prostaglandin F1 alpha (6-KF), and thromboxane B2 (TxB2) by specific radioimmunoassays. In normal women (n = 10), the concentrations of prostaglandins in peritoneal fluid were (mean +/- SE): PGE2 = 0.79 +/- 0.26, PGF2 alpha = 0.60 +/- 0.18, 6-KF = 0.48 +/- 0.19, and TxB2 = 0.23 +/- 0.09 ng/ml; in women with endometriosis (n = 16): PGE2 = 1.43 +/- 0.72, PGF2 alpha = 1.52 +/- 0.59, 6-KF = 3.32 +/- 0.71, and TxB2 = 1.14 +/- 0.69 ng/ml; in women with chronic pelvic inflammatory disease and/or obstructed tubes (n = 19): PGE2 = 1.94 +/- 1.04, PGF2 alpha = 1.20 +/- 0.61, 6-KF = 1.55 +/- 0.40, and TxB2 = 0.64 +/- 0.24 ng/ml; in women with pelvic pain without any visible pathologic condition (n = 4): PGE2 = 1.11 +/- 0.66, PGF2 alpha = 0.73 +/- 0.55, 6-KF = 1.35 +/- 0.35, and TxB2 = 0.39 +/- 0.17. The mean volumes of peritoneal fluid recovered were 10 to 16 ml and were not significantly different between the groups. Except for a significantly elevated concentration of 6-KF in the peritoneal fluid of women with endometriosis compared to normal women (p = less than 0.02), the prostaglandins measured did not differ significantly between the groups of women studied. The possible significance of elevated 6-KF in the peritoneal fluid of women with endometriosis is discussed.

To determine the temporal relationship between immunoreactive chorionic gonadotropin, chorionic gonadotropin receptors, and implantation of the rabbit blastocyst, (1) immunoreactive chorionic gonadotropin in plasma, uterine flushings and blastocysts; (2) chorionic gonadotropin receptors on blastocysts (day 5 and 6) and embryonic and interembryonic segments of the uterus (day 7); and (3) chorionic gonadotropin receptors on the endometrium and myometrium (day 1 through 6) were measured. Binding of I125-labeled beta-subunit of human chorionic gonadotropin (hCG) by cell membranes from blastocysts increased significantly from 6.0 +/- 1.1 fmol/mg of protein (mean +/- SE) on day 5 (N = 6) to 16.1 +/- 1.3 fmol/mg of protein on day 6 (n = 6) (P less than 0.001). Immunoreactive chorionic gonadotropin levels in blastocyst fluid increased from 0.3 ng/ml of day 5 to 0.65 ng/ml on day 6. Specific binding of I125-labeled hCG was absent in endometrial and myometrial cell membranes before implantation (days 1 to 6) but was found in decidual cells from embryonic segments on day 7. Plasma immunoreactive chorionic gonadotropin or chorionic gonadotropin--like material increased from 6 ng/ml of day 1 to 52 ng/ml on day 7. Uterine flushings had chorionic gonadotropin levels of 0.4 ng/ml of day 2, which increased slowly to 1.0 ng/ml on day 7. Intrauterine instillation of hCG into nonpregnant uterine horns demonstrated transuterine absorption of hCG with plasma hCG levels showing a dose-related response. Our findings demonstrate that (1) immunoreactive chorionic gonadotropin or chorionic gonadotropin--like material is detectable in plasma, uterine flushings, and blastocyst fluid before implantation, (2) chorionic gonadotropin receptors are present on the blastocyst cells before implantation, and (3) the uterus can absorb chorionic gonadotropin from its lumen.