Pulsatile administration of oxytocin for augmentation of labor

In a randomized study, 94 patients with term pregnancies underwent augmentation of labor with either continuous or pulsed (every 8 minutes) intravenous oxytocin infusion. There were no significant differences with respect to the maternal characteristics, cervical dilatation and effacement, induction-to-labor interval, induction-to-delivery interval, cesarean section rate, analgesia for labor, or low Apgar scores. No hyperstimulation was noted in either group. In each group, 20% of the patients had dysfunctional labor patterns, with coupling and tripling of the uterine contractions. The mean +/- SEM oxytocin administered in the pulsed-infusion group was significantly lower than that in the continuous-infusion group (2.1 +/- 0.4 versus 4.1 +/- 0.4 mU/minute; P less than .001). The mean +/- SEM total amount of oxytocin administered was 1300 +/- 332 mU for the pulsed group and 1803 +/- 302 mU for the continuous group, indicating that lower amounts of oxytocin were required for pulsed administration. Our study demonstrates that pulsatile administration of oxytocin is similar in efficacy to our standard continuous oxytocin infusion and requires a lower total amount and rate of oxytocin administered, which may afford a greater margin of safety.

Peri-implantation phase endometrial estrogen and progesterone receptors: effect of ovulation induction with clomiphene citrate

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.

Effect of human chorionic gonadotropin and prostaglandin F2a on progesterone production by human luteal cells

To determine and compare the direct effects of prostaglandin F2a (PGF2a) and human chorionic gonadotropin (hCG) on luteal cell progesterone production in vitro, 9 human corpora lutea obtained at tubal ligation were minced and treated with collagenase to disaggregate luteal cells. Dispersed luteal cells (80% viable) were incubated in air at 37 degrees C in a shaking water bath for 3 h and total progesterone in the media and cells was determined by radioimmunoassay. Optimum progesterone production was obtained using 25,000 or more cells per incubate and an incubation time of 2-4 h. hCG-stimulated progesterone production increased significantly with 0.01 IU to as high as 100 IU. In the early luteal phase (days 1-5 post ovulation or days 15-20 of the luteal phase), PGF2a (10-1000 ng) significantly inhibited progesterone production but significantly stimulated progesterone production in the mid-luteal phase (days 21-25). PGF2a had no effect on luteal cell progesterone production in the late luteal phase (days 26-30). This age-dependent direct effect of PGF2a on human luteal cell progesterone production in vitro indicates a role for PGF2a in the total intragonadal regulation of progesterone output, possibly through a paracrine or autocrine manner directed towards synchronizing luteal progesterone secretion and endometrial preparation for nidation.

Expression of the human relaxin gene in the corpus luteum of the menstrual cycle and in the prostate

DNA-RNA hybridization has been used to assess the presence of relaxin gene transcripts in human luteal tissues of pregnancy and the menstrual cycle, as well as in the human testis and prostate. The results imply a substantial capacity for hormone biosynthesis in the mid to late luteal phase of the ovary in non-pregnant women. In men the prostate has been shown also to express relaxin gene transcripts, though levels are low. The testis appears negative. The results suggest that functions for relaxin must be sought also outside pregnancy.

The luteinizing hormone surge: timing and characteristics in the plasma and urine after clomiphene citrate treatment

Clomiphene citrate (CC) has been used to influence the timing of ovulation. To evaluate the effects of CC on the timing of the luteinizing hormone (LH) surge, we examined the LH surge in 10 cycling normal women for 3 cycles each, during an untreated cycle (control) and during treatment with 50 mg CC (CC 50) and 150 mg CC (CC 150) daily on days 5 to 9. Length of control cycles (mean +/- standard error of the mean) was 28.5 +/- 1.1 days and was not significantly different from either CC 50 (28.2 +/- 0.6 days) or CC 150 cycles (29.0 +/- 0.4 days). LH surge occurred on day 16.4 +/- 1.2 in control, 16.5 +/- 0.5 in CC 50, and 17.1 +/- 0.7 in CC 150 cycles. Similarly, luteal phase lengths were not significantly affected by CC treatment. Individually, however, the effect of CC on the timing of the LH surge depended on when the LH surge occurred in corresponding control cycles. If the control cycle LH surge occurred on day 16 or earlier, CC significantly delayed it. If the normal LH surge occurred on day 18 or later, CC advanced it. During CC 50 treatment, the LH surge was advanced by 1 to 7 days in 3 cycles, unchanged in 2, and delayed in 5 cycles by 1 to 9 days. Detection of urinary LH surge was reliable in CC-treated cycles and correlated well with the day of plasma LH surge.(ABSTRACT TRUNCATED AT 250 WORDS)

Cortical and trabecular bone mineral content in women with endometriosis: effect of gonadotropin-releasing hormone agonist and danazol

Cortical bone (distal radius and ulna) and trabecular bone mineral content of the thoracolumbar vertebrae (T-12 to L-4) were measured with single-photon absorptiometry and quantitative computed tomography, respectively, in 55 women with laparoscopically staged endometriosis before, during, and after treatment with a gonadotropin-releasing hormone agonist (GnRH-a) or danazol. Mean pretreatment potassium phosphate mineral contents of T-12 to L-4 were 174 to 201 mg/ml in stage I to IV endometriosis and were within the 100 to 115th percentile of normal women. Similarly, cortical bone mineral contents were normal and were not significantly affected by either medication. Trabecular bone decreased significantly to 92.6 +/- 1.7% (n = 11, P less than 0.001) and 92.3 +/- 2.5% (n = 7, P less than 0.01) of baseline year after 6 months and 9 months of GnRH-a treatment and remained significantly depressed at 95.8 +/- 1.9% (P less than 0.0025) and 94.8 +/- 2.5% (P less than 0.005) 6 months after stopping treatment. Thus, cortical and trabecular bone mineral contents of women with endometriosis are normal, but treatment with GnRH-a induced significant loss of trabecular bone.

Evolving concepts of oxytocin for induction of labor

Based on findings of maternal and fetal circulating oxytocin levels during spontaneous labor and the available information on oxytocin secretion patterns, the dosage and mode of administration of oxytocin for induction of labor is discussed. It is recommended that intravenous infusion rates should not exceed 2 to 8 mU/min. Oxytocin administered in a pulsatile fashion beginning with 1 mU/min every 8 minutes with doubling the pulse dose every 24 minutes is equally as efficient as continuous infusion. Because both the peak levels and the total dose of oxytocin needed for induction are lower with pulsatile than continuous administration, the risk of adverse effects for the mother and the fetus is significantly reduced.

Human corpus luteum: luteinizing hormone and chorionic gonadotropin receptors during the menstrual cycle

To characterize and determine the concentration of LH/hCG receptors in human corpora lutea of the menstrual cycle, we measured occupied and unoccupied receptors and determined the association (Ka) and dissociation (Kd) constants individually in 23 corpora lutea (CL) and 4 corpora albicantia obtained at the time of tubal ligation from 25 normal cycling women. We found no [125I]hCG binding in any of the corpora albicantia. Scatchard plot analysis for each CL revealed a linear binding plot indicative of a single set of LH/hCG receptors. The mean concentration of unoccupied receptors was 36 +/- 10 (+/- SE) fmol/mg protein in the early luteal phase (days 15-19; n = 5), 64 +/- 11 fmol/mg protein in the midluteal phase (days 20-25; n = 13), and 42 +/- 19 fmol/mg protein in the late luteal phase (days 26-30; n = 5). The concentrations of occupied receptors were 56 +/- 8, 46 +/- 6, and 54 +/- 12 fmol/mg protein in the early, mid-, and late luteal phases, respectively. Total (occupied plus unoccupied) receptor concentrations reached maximum levels of 110 +/- 11 fmol/mg protein in the midluteal phase. Ka increased progressively from 12 +/- 4 X 10(9) mol/L-1 in the early luteal phase to 19 +/- 7 X 10(9) and 21 +/- 8 X 10(9) mol/L-1 in the mid- and late luteal phases. We conclude that in normal CL, 1) total and unoccupied LH/hCG receptor levels parallel progesterone secretion; 2) changes in the binding affinity may be important in sustaining and/or rescuing the CL; and 3) loss of LH/hCG receptors is probably related to luteolysis.

Human corpus luteum secretion of relaxin, oxytocin, and progesterone

To determine whether the human corpus luteum is a source of relaxin and oxytocin, we measured the concentrations of these peptides in plasma obtained from the ovarian veins of ovaries with and without a corpus luteum and compared these to peripheral plasma levels. Peripheral and ovarian venous blood samples were obtained from 34 nonpregnant women, 13 during the luteal phase and 21 during the follicular phase of their cycles, and from a 6-week pregnant woman. Plasma relaxin, oxytocin, and progesterone concentrations were determined by sensitive and specific RIAs. Plasma relaxin levels were not detectable (less than 0.16 microgram/L) in peripheral or ovarian venous plasma not draining a corpus luteum. The mean relaxin concentration in plasma draining an ovary with a corpus luteum was 0.41 +/- 0.09 (+/- SE) microgram/L. Oxytocin levels also were significantly higher in plasma draining an ovary with a corpus luteum (6.70 +/- 1.86 pmol/L) than in that draining the ovary with no corpus luteum (1.58 +/- 0.09 pmol/L; P less than 0.01) or in peripheral plasma (1.58 +/- 0.09 pmol/L; P less than 0.025). The mean progesterone concentration also was highest in plasma draining an ovary with a corpus luteum (210.2 +/- 50.5 nmol/L) compared with those in plasma from the contralateral ovarian vein (40.3 +/- 16.5 nmol/L P less than 0.005) and peripheral plasma (30.2 +/- 5.7 nmol/L; P less than 0.005) during the luteal phase. In a woman who was 6 weeks pregnant, plasma draining the ovary with a corpus luteum had 1.9 micrograms relaxin/L, but only 0.49 pmol/L oxytocin; the latter was similar to concentrations in noncorpus luteum-bearing ovarian venous plasma. These findings indicate that the human corpus luteum secretes relaxin, oxytocin, and progesterone. Both ovarian oxytocin and relaxin may function as paracrine or autocrine modulators of luteal function.

Plasma and peritoneal fluid levels of CA 125 in women with endometriosis

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.

Nonsteroidal anti-inflammatory drugs and changing attitudes toward dysmenorrhea

Dysmenorrhea, which may be primary or secondary, is the occurrence of painful uterine cramps during menstruation. Until a decade ago, medical and social attitudes toward dysmenorrhea were shrouded with folklore, psychoanalytical profiles, or psychosomatic bases. In secondary dysmenorrhea, there is a visible pelvic lesion to account for the pain, whereas only a biochemical abnormality is responsible for primary dysmenorrhea. Recent advances in the biochemistry of prostaglandins and their role in the pathophysiology of primary dysmenorrhea and intrauterine device (IUD)-induced dysmenorrhea have now firmly established a rational basis for the disorder. In primary dysmenorrhea, menstrual prostaglandin release is significantly increased but can be readily suppressed to normal levels when nonsteroidal anti-inflammatory drugs (NSAIDs) capable of inhibiting cyclo-oxygenase are given during menstruation. Many clinical trials (controlled and uncontrolled) have demonstrated the efficacy of NSAIDs such as the fenamates, indole-acetic acid derivatives, and arylpropionic acid derivatives in relieving primary dysmenorrhea as well as IUD-induced dysmenorrhea that is also due to elevated prostaglandin levels. With a few of these NSAIDs, it has been shown that the relief of pain is associated with a significant decrease in menstrual fluid prostaglandin levels. Cumulative data of clinical trials indicate that with the effective NSAIDs, 80 percent of patients with significant primary dysmenorrhea can be adequately relieved. Ongoing studies suggest that in some women, endometrial leukotriene, but not PGF2a production, is increased. With the official approval and availability of several effective NSAIDs for the specific treatment of primary dysmenorrhea in the United States, women who have primary dysmenorrhea have been greatly relieved and their productivity increased. Primary dysmenorrhea affects 50 percent of postpubescent women and absenteeism among the severe dysmenorrheics has been estimated to cause about 600 million lost working hours or 2 billion dollars annually. Thus, an effective, simple, and safe treatment of primary dysmenorrhea for two to three days during menstruation will not only have a positive economic impact but will also enhance the quality of life. The availability of effective dysmenorrhea therapy with NSAIDs has induced greater expectations of relief by the patient, as well as greater willingness to seek medical help, a more rational approach to patient management by physicians, changes in attitude toward women with primary dysmenorrhea, and the debunking of myths about dysmenorrhea that often have been perpetuated as fact.(ABSTRACT TRUNCATED AT 400 WORDS)

Baboon corpus luteum oxytocin: an intragonadal peptide modulator of luteal function

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.

Luteal phase salivary progesterone concentrations in ovulation-induced cycles

Serial paired plasma and salivary progesterone (P) levels were determined in 21 ovulation-induced cycles of 13 women and in 162 luteal saliva samples of 21 normal cycling women. Mean +/- standard error of the mean (SEM) salivary P levels in all ovulation-induced cycles were similar to normal cycles and were 294 +/- 31.5 to 499 +/- 75 pg/ml, whereas the corresponding plasma P levels were 24.9 +/- 5.0 to 51.4 +/- 16.6 ng/ml. Paired plasma and salivary P levels correlated significantly in women induced with clomiphene citrate (r = 0.82), follicle-stimulating hormone (r = 0.80), human menopausal gonadotropins (r = 0.78), and in those who became pregnant (r = 0.95). Luteal phase salivary P levels were 1.0% to 1.3% of the corresponding plasma levels in ovulation-induced cycles. These findings indicate that salivary P may be a useful and convenient alternative to plasma P for assessing ovulation.

Seminal plasma proteins of fertile and infertile men analyzed by two-dimensional electrophoresis

Sperm-free seminal plasma from seminal fluid ejaculate of fertile and infertile men obtained in the presence and absence of aprotinin (500 kallikrein inhibitor units per milliliter) was analyzed by two-dimensional electrophoresis followed by silver staining. To evaluate postliquefaction proteolytic breakdown of seminal plasma proteins, protease inhibitors were added to the semen at 15, 30, and 60 minutes after ejaculation. Most seminal plasma proteins in normospermic men (n = 4) had molecular weights of 30,000 to 70,000 and were similar to those present in serum. The major non-serum protein in seminal plasma of all men was a basic product with an approximate molecular weight of 40,000. A group of proteins (molecular weights = 20,000 to 23,000) in seminal plasma analyzed immediately after liquefaction was detected in oligospermic men (n = 4) but not in normospermic men (n = 4) or azoospermic men (n = 4). When protease inhibitor was added to normospermic semen at greater than or equal to 15 minutes after liquefaction, these proteins (molecular weight = 20,000 to 23,000) and another group of proteins (molecular weights = 40,000 to 43,000) were readily identifiable but were further enhanced in the absence of protease inhibitors. These findings suggest that oligospermic men may have accelerated proteolysis of sperm or seminal plasma proteins that may contribute to subfertility.

Protein, progesterone, and protease inhibitors in uterine and peritoneal fluids of women with endometriosis

This study was undertaken to determine whether women with endometriosis have altered protein, progesterone (P), and protease inhibitor concentrations in their uterine fluid and peritoneal fluid (PF) compared with controls at different phases of the menstrual cycle. Uterine flushings (UFs), PF, and blood were obtained during the follicular and luteal phases of the cycle from 29 normal women and 16 women who were diagnosed as having endometriosis. Protein content in UF did not change significantly throughout the cycle in either group. However, PF protein in patients with endometriosis was significantly (P less than 0.05) higher than in controls during the luteal phase. Total UF P was significantly (P less than 0.05) reduced in women with endometriosis during the late luteal phase. During the early luteal phase, trypsin inhibitory activity in UF from normal women was significantly (P less than 0.05) higher than at any other phase of the cycle, whereas inhibitory activity in UF from patients with endometriosis remained relatively constant. Patients with endometriosis had significantly (P less than 0.05) higher total activity in PF during the early luteal phase than did controls. These results indicate that women suffering from endometriosis have significantly lower levels of P and less protease inhibitor within their uterine cavity during the luteal phase of the cycle, and significantly higher concentrations of protein and protease inhibitor in PF during the luteal phase.

The effect of estrogen-progestin treatment on opioid control of gonadotropin and prolactin secretion in postmenopausal women

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.

Hormones and cervical ripening: dehydroepiandrosterone sulfate, estradiol, estriol, and progesterone

Fetal adrenal steroids have been shown to be important in the timing of parturition. Since dehydroepiandrosterone sulfate is converted to estrogen, which is important in cervical softening, levels of dehydroepiandrosterone sulfate together with those of estradiol, estriol, and progesterone were measured and compared in pregnant women undergoing induction of labor with ripe and unripe uterine cervices. While there were no differences between the levels of estradiol, estriol and progesterone in the two groups of women, dehydroepiandrosterone sulfate was significantly elevated in the group of women with ripe cervices. These findings suggest that cervical changes preceding the onset of labor are associated with a significant elevation of maternal dehydroepiandrosterone sulfate levels. Changes in maternal plasma estradiol, estriol, and progesterone levels do not appear to be clinically related to cervical ripeness.

Adhesion formation and uterine tube healing in the rabbit: a controlled study of the effect of ibuprofen and flurbiprofen

To determine if the prostaglandin synthetase inhibitors ibuprofen and flurbiprofen can suppress postoperative adhesion formation, New Zealand White rabbits that had uterine tubal ligation underwent uterine tube reanastomosis and were given either saline solution (controls), 75 mg of ibuprofen intravenously every 6 hours, or 12.5 mg of flurbiprofen intravenously every 6 hours for 8 doses after operation. Both ibuprofen and flurbiprofen significantly reduced postoperative adhesions (p less than 0.025). With histologic indices of tissue reunion, ibuprofen and flurbiprofen were associated with significantly less scar thickness than controls (p less than 0.001) but did not have any significant effect on mucosal regeneration, foreign body reaction, and muscularis disruption. When all four histologic indices were compared, flurbiprofen but not ibuprofen had a significantly lower score than controls, indicating the greater potency of flurbiprofen over ibuprofen. Our findings show that ibuprofen and flurbiprofen can suppress perioperative and postoperative surgically induced inflammatory response associated with healing and thereby reduce adhesion formation and scar thickness.

A simple method for the collection of human uterine flushing

A method for the collection of human uterine lavages using a double-barreled cannula that allows for simultaneous injection and aspiration of the flushing is described. The method is simple and quick, is precise, and gives lavage volume recoveries of 77% to 100%. Protein determination of the human uterine flushing gave measurable levels, which are lower than in the plasma. Access to human uterine luminal secretions by this method, which can be repeatedly performed, can facilitate investigations into the sequential biochemical and hormonal uterine secretions in vivo in the same individual.

Human ovarian oxytocin: its source and relationship to steroid hormones

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.

Paracrine regulation of luteal function

The mechanisms controlling luteal function may involve factors that are produced both within the corpus luteum and outside the ovary. The process of luteal control appears to involve a series of molecular species, proteins, peptides, steroids and prostaglandins. Each of these factors may act independently or in concert modifying the actions of one another. The effect of GnRH on luteal function has not been completely examined and thus its significance is unclear. The neurohypophyseal peptides, oxytocin and arginine vasopressin, in combination with LH, prolactin, oestrogens and prostaglandins may play an important regulatory role on the corpus luteum.

Opioid regulation of pituitary gonadotropins and prolactin in women using oral contraceptives

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.

Current concepts in the etiology and treatment of primary dysmenorrhea

Primary dysmenorrhea may affect as many as 40 percent of all adult women, temporarily disabling one-tenth of them. The etiology of this condition may be related to excess production of prostaglandins by the endometrium following decline in progesterone levels consequent to corpus luteum regression. It is proposed that increased prostaglandin levels produce increased myometrial contractility and uterine ischemia and sensitization of pain fibers, resulting in pelvic pain. Administration of nonsteroidal anti-inflammatory agents which block the cyclooxygenase enzyme of the arachidonic acid cascade is an effective treatment for primary dysmenorrhea, as is oral contraceptive therapy. Criteria for an ideal prostaglandin synthetase inhibitor are described.

The effects of steroid hormones and gonadotropins on in vitro placental conversion of pregnenolone to progesterone

Using human term placental mitochondrial preparations, optimal conversion of [3H]pregnenolone to [3H]progesterone was obtained at 30 min incubation and with a mitochondrial protein content of 2.5-3.5 mg/ml. Estradiol, estrone, progesterone and testosterone in a dose range of 0.03-8.66 mumol inhibited the in vitro conversion of [3H]pregnenolone to [3H]progesterone by placental homogenates. All four steroids inhibited the pregnenolone to progesterone conversion in a dose-dependent manner. The ID50 (dose required to inhibit conversion of pregnenolone to progesterone by 50%) was 0.04 mumol for estradiol, 0.13 mumol for testosterone, 0.3 mumol for progesterone and 1.0 mumol for estriol. Neither gonadotropin releasing hormone (50-1000 ng) nor human chorionic gonadotropin (5-500 IU) affected the placental basal conversion rate of pregnenolone to progesterone in vitro. Our findings indicate that steroid hormones such as estradiol, estrone, testosterone and progesterone can inhibit local placental progesterone biosynthesis through inhibition of the enzyme complex 5-ene-3 beta-hydroxysteroid dehydrogenase.

Dysmenorrhea

Dysmenorrhea affects over 50% of menstruating women and causes extensive personal and public health problems, a high degree of absenteeism and severe economic loss. In primary dysmenorrhea there is no macroscopically identifiable pelvic pathology, while in secondary dysmenorrhea gross pathology is present in the pelvic structures. With primary dysmenorrhea the pain is suprapubic and spasmodic, and associated symptoms may be present. Characteristically dysmenorrhea starts at or shortly after menarche. The pain lasts for 48-72 hours during the menstrual flow and is most severe during the first or second day of menstruation. It is now clear that in many women with primary dysmenorrhea the pathophysiology is due to increased and/or abnormal uterine activity because of the excessive production and release of uterine prostaglandins. Treatment with many of the prostaglandin synthetase inhibitors (nonsteroidal antiinflammatory drugs) will produce significant relief from dysmenorrhea and a concomitant decrease in menstrual fluid prostaglandins. For dysmenorrheic women who desire oral contraception, this agent will relieve the dysmenorrhea by suppressing endometrial growth, thus resulting in a decrease in the menstrual flow as well as in menstrual fluid prostaglandins. For those not requiring oral contraception the drug of choice for primary dysmenorrhea remains a prostaglandin inhibitor. Laparoscopy need be resorted to only if a pelvic abnormality is detected on examination or if treatment with prostaglandin inhibitors for up to six months is not significantly effective. In secondary dysmenorrhea, relief is obtained when the pelvic pathology--such as ovarian cysts, uterine fibroids, adhesions, cervical stenosis, congenital malformation of the uterus and endometriosis--is treated. In women using IUDs the dysmenorrhea is readily controlled with prostaglandin inhibitors since the underlying pathophysiology is excessive prostaglandin production and release.