The postmenopausal ovary is not a major androgen-producing gland.

It is currently believed that the postmenopausal ovary remains a gonadotropin-driven, androgen-producing gland. However, the adrenal contribution to circulating androgen levels may explain some conflicting results previously reported. In addition, the steroidogenic potential and gonadotropin responsiveness of the postmenopausal ovary have not been recently reassessed. Plasma T, bioavailable T, free T, androstenedione (Adione), and dehydroepiandrosterone sulfate levels were measured in postmenopausal or ovariectomized women with complete adrenal insufficiency, compared with women with intact adrenals. A stimulation human chorionic gonadotropin test (on d 0, 3, and 6) was performed in postmenopausal women with adrenal insufficiency. Dexamethasone was administered for 4 d in postmenopausal women with intact adrenals. Intraovarian T and androstenedione were also measured in homogenates of ovarian tissue from postmenopausal women. Immunocytochemistry was performed on postmenopausal ovaries and premenopausal controls to detect the presence of steroidogenic enzymes (P-450 aromatase, P-450 SCC, 3beta HSD, and P-450 C17) and gonadotropin receptors. Plasma androgen levels were below or close to the limit of the assay in all women with adrenal insufficiency. They were similar in postmenopausal and oophorectomized women with normal adrenals. No hormonal changes were observed after human chorionic gonadotropin injections in women with adrenal insufficiency. In contrast, a dramatic decrease of all steroids was observed after dexamethasone administration in postmenopausal women with intact adrenals. Intraovarian T and androstenedione levels were negligible in postmenopausal ovarian tissue. P-450 aromatase was absent from the 17 ovaries studied, and the enzymes for androgen biosynthesis were either absent (n = 13) or present in very low amounts (n = 4). In all the postmenopausal ovaries, FSH and LH receptors were completely absent. In the absence of adrenal steroids, postmenopausal women have no circulating androgens. This result is consistent with the immunocytochemical studies showing the almost constantly absent steroidogenic enzymes and LH receptors in the postmenopausal ovary. Thus, the climacteric ovary is not a critical source of androgens. The arrest of androgen secretion after menopause may impact significantly on women's health.

Effects of human recombinant luteinizing hormone and follicle-stimulating hormone in patients with acquired hypogonadotropic hypogonadism: study of Sertoli and Leydig cell secretions and interactions.

UNLABELLED: Experimental data suggest that FSH-stimulated Sertoli cells can enhance LH-induced Leydig cell testosterone (T) production. The function of Leydig and Sertoli cells can be selectively studied by using recombinant human LH (rhLH) and recombinant human FSH (rhFSH) in patients with complete gonadotropin deficiency. The aim of the present study was to assess the secretion of testicular T, estradiol (E2), and inhibin B and the physiological relevance of the Sertoli-Leydig cell interaction in man. For that purpose, six patients with acquired complete hypogonadotropic hypogonadism received the following treatments for three periods of 1 month in a random order: 1) rhLH, 900 IU/day sc; 2) rhFSH, 150 IU/day sc; and 3) combined rhLH/rhFSH treatments. Each treatment period was separated by a washout period of 15 days. Plasma LH, FSH, T, E2, and inhibin B were measured before and every 10 days during each treatment. During rhLH administration, mean plasma LH levels rose significantly from 0.4 +/- 0.2 IU/L to 11.7 +/- 1.2 IU/L (P < 0.01) and plasma FSH levels did not change. rhFSH administration induced a significant increase in plasma FSH levels (from 0.5 +/- 0.4 to 12.1 +/- 1.4 IU/L; P < 0.01), whereas mean plasma LH levels remained low. Mean plasma E2 levels were unchanged during rhFSH treatment, but they increased significantly during rhLH from 22 +/- 4 to 54 +/- 8 pmol/L (P < 0.01) and during rhLH plus rhFSH administration. rhFSH treatment induced a sustained elevation of mean plasma inhibin B levels from 58 +/- 13 to 175 +/- 25 pg/mL (P < 0.01), similar to the increase occurring during rhFSH plus rhLH administration. In contrast, mean plasma inhibin B levels did not increase during rhLH administration. Finally, a similar and significant increase in mean plasma T levels occurred during both rhLH and rhLH plus rhFSH treatment from 0.9 +/- 0.3 to 5.4 +/- 0.7 nmol/L (P < 0.01) and from 1.0 +/- 0.4 to 6.0 +/- 0.9 nmol/L (P < 0.01), respectively. In contrast, during rhFSH treatment mean plasma T levels remained unchanged when compared with baseline. IN CONCLUSION: 1) the increase of plasma E2 induced by rhLH and the absence of effect of rhFSH confirm that Leydig cells are the major site of testicular E2 production in man; 2) the secretion of inhibin B is increased by rhFSH and not by rhLH, and, thus, Sertoli cells seem to be the main source of inhibin B production; and 3) the increase of plasma T induced by rhLH is not enhanced by rhFSH. These results suggest that the stimulatory effect of FSH on Leydig cell steroidogenesis by a Sertoli cell paracrine factor does not seem to play a major physiologic role in man.

Measurement of plasma free luteinizing hormone beta-subunit in women.

Little is known about the physiological secretion of the free beta-subunit of LH (LHbeta). The aim of this study was to compare in women the secretion of LHbeta, using sensitive and specific two-site immunoassays, with dimeric LH and the free common alpha-subunit (FAS). The LHbeta assay does not recognize the dimeric LH and cross-reacts only with free hCG beta-subunit (CGbeta). Thus, all of the plasma samples were also tested with a highly specific immunoradiometric assay for free CGbeta. Molar concentrations (i.e. picomoles per L) were used to compare the plasma levels of LH and its free subunits. Plasma LH, LHbeta, FAS, and CGbeta levels were measured in five normally cycling women during the early follicular phase and the ovulatory peak of LH. The pulsatile profiles of LH, LHbeta, FAS, and CGbeta were studied in five postmenopausal women before and 21 days after injection of a depot preparation of the GnRH agonist D-Trp6 (3.75 mg, im) and in five women with functional hypothalamic amenorrhea (FHA), i.e. low plasma LH levels, during pulsatile GnRH administration (20 microg/pulse, 90 min, sc). Afterward, one of the patients with FHA received a single sc injection of 1350 U recombinant human LH, and plasma LH, LHbeta, FAS, and CGbeta levels were measured and compared with the high plasma levels of one postmenopausal woman. In cycling women, basal plasma LHbeta and CGbeta levels were below the detection limit of the assays (1.34 and 0.65 pmol/L, respectively), and plasma FAS levels were 13.60 +/- 0.13 pmol/L. During the LH surge, there was a parallel increase in LH, LHbeta, and FAS. Plasma CGbeta levels remained undetectable. In normal postmenopausal women, basal plasma dimeric LH, LHbeta, and FAS levels were increased in parallel, and their pulsatile profiles were similar, without measurable plasma CGbeta levels. After D-Trp6 administration, plasma LH and LHbeta levels were completely suppressed, whereas plasma FAS levels increased, and plasma CGbeta remained below 0.65 pmol/L. In FHA women, basal plasma levels of LH and FAS were low, without detectable LHbeta and CGbeta levels. During pulsatile GnRH administration, LHbeta became detectable, and pulses were synchronous with those of LH and FAS. The secretion of LH and LHbeta was almost equimolar. Plasma CGbeta levels remained undetectable. In the patient with FHA, administration of recombinant human LH increased only plasma LH levels, whereas plasma LHbeta and FAS levels remained very low. In conclusion, when the production of dimeric LH increases, a concomitant, parallel, and almost equimolar hypersecretion of uncombined and biologically inactive LHbeta occurs. Like the alpha-subunit, LHbeta may be secreted in the dissociated free form. This can lead to pitfalls during clinical investigations if assays of free CGbeta display some cross-reaction with free LHbeta.

The antigonadotropic activity of a 19-nor-progesterone derivative is exerted both at the hypothalamic and pituitary levels in women.

We have previously shown in postmenopausal women that a 19-nor-progesterone derivative, nomegestrol acetate (NOMA) had a strong antigonadotropic activity and that this effect was not mediated via the androgen receptor. The aim of the present study was to further assess the action of this progestin on gonadotropin secretion in women. To demonstrate at which level of the hypothalamo-pituitary-ovarian axis the gonadotropin inhibition was exerted, 10 normally cycling (NC) women, 3 women with a gonadotropin-independent ovarian function [McCune-Albright (MCA) syndrome], and 5 women with functional hypothalamic amenorrhea (FHA) participated in the study. NC women were treated orally with 5 mg NOMA for 21 days, after one control cycle. Plasma estradiol (E2) and progesterone, LH, and FSH levels were measured during each cycle. A frequent sampling study (every 10 min for 4 h), followed by a classic GnRH test (100 microg, i.v.), was performed on day 11. Women with MCA were studied before, during NOMA, and after long-acting GnRH agonist administration. In women with FHA, pulsatile GnRH (20 microg s.c., every 90 min) was given for two cycles with or without NOMA (5 mg for 21 days). In all NC women, ovulation was suppressed by NOMA. Mean plasma LH levels, LH pulse frequency, and the LH response to exogenous GnRH were significantly decreased. In MCA, neither NOMA nor GnRH agonist modified multiple ovarian cysts on ultrasound or plasma E2, levels which remained elevated, ruling out a direct ovarian effect. In FHA, pulsatile GnRH administration recreated a normal ovulatory menstrual cycle. Addition of NOMA prevented the increase of plasma E2, decreased the amplitude of LH pulses, and prevented ovulation. In view of this unexpected action of NOMA at the pituitary level, seven samples of normal human female pituitaries were tested for the presence of progesterone receptor (PR) using a double labeling immunocytochemical technique. The presence of PR was detected in the seven human pituitary tissues. In addition, PR was found to be expressed only in gonadotroph cells. In conclusion, NOMA, a 19-nor-P derivative, has a potent antigonadotropic activity exerted at the hypothalamic level, inhibiting ovulation in NC women. In women with FHA, NOMA decreased the gonadotropin stimulation induced by pulsatile GnRH administration. According to the presence of PR in gonadotroph cells of normal human pituitaries, 19-nor-progesterone derivatives may also act on the gonadotropin secretion at the pituitary level.

Functional hypothalamic amenorrhoea: a partial and reversible gonadotrophin deficiency of nutritional origin.

OBJECTIVE: Functional hypothalamic amenorrhoea (FHA) is a consequence of low dietary intake as observed in two major pathophysiological conditions, anorexia nervosa and/or intensive physical exercise. The aim of the present study was to assess in women with FHA and normal body mass index (BMI) and apparently normal daily activities, the degree of impairment of GnRH secretion, its nutritional origin and its reversibility. PATIENTS: Twelve women (22-35 years) with FHA not related with exercise and 12 age and BMI matched menstruating controls (NC) were studied. Six women with congenital hypothalamic hypogonadism (CHH), representative of complete gonadotrophin deficiency, were also enrolled for comparison. DESIGN: Plasma oestradiol (E2) and androstenedione (A) levels were measured and the pulsatile profile of LH was studied. A GnRH agonist test, using 100 micrograms S/C of DTrp6 GnRH (Triptorelin) was performed (sampling every 2 h for 24 h). Dietary intake, body composition and nutritional markers (FT3, ferritin, retinol binding protein (RBP), SHBG, IGF-1 and leptin) were measured. All the women with FHA were advised to normalize their diet during four months. The same studies were performed if nutritional markers and body composition were normalized. RESULTS: In FHA, mean plasma E2 and A levels were low. LH pulse frequency and amplitude were significantly reduced compared to NC (P < 0.005). FSH/LH ratio increased rapidly after triptorelin with a significant increase in plasma E2 levels between 18 and 24 h. In contrast, no response to triptorelin was observed in women with CHH. The fat body mass was lower and the lean body mass higher in FHA than in NC. Marked differences in nutritional intake were identified, with altered dietary composition. FHA consumed significantly less fat (P < 0.001) and less carbohydrate (P = NS) than the BMI-matched controls. Mean plasma levels of SHBG were increased whereas mean plasma levels of FT3, ferritin, RBP, IGF-1, and leptin were significantly decreased. Only three patients with FHA kept a balanced diet and improved their body composition after 4 months. LH pulsatile profile and response to triptorelin challenge were normalized in these patients. CONCLUSION: Mild dieting, close to normal but prolonged and characterized by an important fat restriction, is able to interfere with gonadotrophin secretion. Assessment of nutritional markers allows recognition of mild nutritional insufficiency as a common cause of FHAs. The gonadotrophin deficiency is partial and may be reversible after improvement of nutritional intake and body composition.

[Large cell variant of small cell carcinoma of the ovary with hypercalcemia]. / Variante à grandes cellules d'un carcinome à petites cellules de l'ovaire avec hypercalcémie.

We describe an original distinct type of ovarian small cell carcinoma: large cell variant. The distinctive histologic features of tumor cells were the presence of large nuclei with prominent nucleoli and abundant eosinophilic cytoplasm. Immunohistochemistry revealed strong diffuse vimentin, smooth muscle actin positivity and slight reactivity with epithelial markers. Electron microscopy showed aggregates of intermediate filaments, intercellular attachments and no dense core granules. This tumor is associated with paraendocrine hypercalcemia in two thirds of cases. Parathyroid hormone-related protein was focally positive. This tumor is characterized as a very lethal neoplasm, occurring primarily in young women.

Panhypopituitarism as a model to study the metabolism of dehydroepiandrosterone (DHEA) in humans.

The physiological importance and therapeutical interest of dehydroepiandrosterone (DHEA) and its sulfate ester (DHEAS) are still controversial. Panhypopituitarism is characterized by the absence of secretion of adrenal and gonadal steroids and thus the production of their metabolites. The conversion of DHEA given orally into delta 5 derivatives, androgens, androgen metabolites, and estrogens was studied in ten patients with complete panhypopituitarism. Sex steroid therapy was withdrawn for at least 2 months. Each patient received, at 1-month intervals and in a random order, two single oral doses of DHEA (50 mg and 200 mg) and placebo. During each treatment, urine samples were collected for 24 h, and blood samples were drawn at hourly intervals for 8 h. In patients with pituitary deficiency, plasma DHEA and DHEAS were not detectable and increased, with the 50 mg dose, up to levels observed in young adults. The administration of 200 mg of DHEA induced an increase of both steroids to supraphysiological plasma levels. A small increase of delta 5-androstenediol was observed. In contrast, the increase of plasma delta 4-androstenedione was important and dose dependent. DHEA was also converted into the potent sex steroid testosterone (T). The administration of a 50 mg dose of DHEA restored plasma T to levels similar to those observed in young women. The 200 mg dose induced an important increase of plasma T, slightly below the levels observed in normal men. The increase of plasma dihydrotestosterone levels was small at both doses of DHEA, in contrast with the large conversion of DHEA into androsterone glucuronide and androstanediol glucuronide. Finally, DHEA administration induced a significant and dose dependent increase of plasma estrogens and particularly of estradiol. In conclusion, this short term study demonstrates that: 1) panhypopituitarism is a model of interest to study the metabolism of DHEA; 2) in the absence of pituitary hormones and of adrenal and gonadal steroids, DHEA given orally is mainly converted into delta 4 derivatives, which in turn are strongly metabolized into 5 alpha-3keto-reduced steroids; 3) a significant increase of sex active hormones was observed in plasma after 200 and even 50 mg of DHEA. Thus, biotransformation of DHEA into potent androgens and estrogens may explain several of the reported beneficial actions of this steroid in aging people.

Luteinizing hormone/human chorionic gonadotropin receptors in breast cancer.

Recent studies have suggested that human choriogonadotropin (hCG), in addition to its function in regulating steroidogenesis, may also play a role as a growth factor. Immunocytochemistry using two different monoclonal antibodies (LHR29 and LHR1055) raised against the human luteinizing hormone/human chorionic gonadotropin (LH/hCG) receptor allowed us to detect this receptor in breast cancer cell lines (T47D, MCF7, and ZR75) in individual cancer biopsies and in benign breast lesions. The receptor was also present in epithelial cells of normal human and sow breast. In the latter, its concentration increased after ovulation. The presence of LH/hCG receptor mRNA was confirmed by reverse transcription-PCR using primers extending over exons 2-4, 5-11, and 9-11. The proportion of LH/hCG-receptor positive cells and the intensity of the immunolabeling varied in individual biopsies, but there was no obvious correlation with the histological type of the cancer. These results are compatible with previous studies suggesting that during pregnancy, hCG is involved in the differentiation of breast glandular epithelium and that this hormone may play an inhibitory role in mammary carcinogenesis and in the growth of breast tumors.

The antigonadotropic activity of progestins (19-nortestosterone and 19-norprogesterone derivatives) is not mediated through the androgen receptor.

To further study the mechanism of the antigonadotropic activity of progestins, the effects of a 19-nortestosterone derivative, norethisterone acetate (NETA), and a 19-norprogesterone derivative, nomegestrol acetate (NOMA), were compared. The aim was to assess whether their action is exerted via the androgen receptor. Ten healthy postmenopausal women were treated for five monthly periods of 24 days separated by 10 days in a randomized cross-over design. Transdermal estradiol, Estraderm TTS (25 micrograms; one patch every 3 days), was given from days 1-24 during the five periods. On the last 12 days, of each estradiol treatment, they all received a placebo, NOMA (5 mg/day), NOMA in association with the nonsteroidal antiandrogen, flutamide (FLU; 250 mg, twice a day), NETA (10 mg/day), or NETA plus FLU. On the other hand, three castrated patients with complete androgen insensitivity (CAI) received NOMA and NETA for two periods of 12 days separated by 3 weeks. In postmenopausal women, the effects of NOMA and NETA on metabolic parameters were studied. Only NETA decreased high density lipoprotein cholesterol. Plasma LH, FSH, and estradiol were measured during each treatment period. A significant decrease in mean plasma LH and FSH levels and their responses to exogenous GnRH was observed with NOMA and NETA treatments compared to placebo (P < 0.001). The pulsatile frequency, but not the amplitude, of LH was significantly decreased during both treatments. Interestingly, the effects of both progestins on gonadotropins were not antagonized by FLU administration. In the patients with CAI, the pulsatile study of gonadotropins was performed before and on day 12 of NOMA and NETA treatments. As in postmenopausal women, both progestins induced similar decreases in LH and FSH. In conclusion, a 19-nortestosterone derivative, NETA, and a 19-norprogesterone derivative, NOMA, have similar antigonadotropic activities. This effect, not antagonized by FLU and observed in patients with CAI, is not mediated via the androgen receptor. The absence of deleterious effects of 19-norprogesterone derivatives on metabolic parameters should favor the therapeutic use of these compounds.

Even after priming with ovarian steroids or pulsatile gonadotropin-releasing hormone administration, naltrexone is unable to induce ovulation in women with functional hypothalamic amenorrhea.

In functional hypothalamic amenorrhea (HA), it has been reported that administration of opioid receptor antagonists restores gonadotropin secretion and ovarian function. However, endogenous opioids may modulate gonadotropin secretion only in the presence of ovarian steroids. To further study these conflicting results, a group of nine women with secondary functional HA who wished to become pregnant were studied. The opiate antagonist naltrexone (Nal; 100 mg/day) was administered for two 30-day periods, starting on either day 22 (Nal 1) of a well characterized replacement regimen with estradiol (E2) and progesterone (P), or on day 22 (Nal 2) of the luteal phase induced by exogenous pulsatile GnRH administration (10 micrograms/pulse, iv, every 90 min). Plasma LH and FSH were measured every 10 min for 8 h before treatment and on day 12 of each treatment period (Nal 1, pulsatile GnRH, and Nal 2). Ovulation was monitored during each treatment. Plasma E2 levels were measured on days 12 and 22, and P levels on day 22 of each treatment. During exogenous E2 and P administration, plasma steroid levels reached luteal phase levels. However, during Nal 1, plasma E2 levels fell to prestudy levels and remained low. No follicular growth occurred, and the pulsatile study showed pretreatment frequency, amplitude, and mean plasma levels of LH. On day 12 of pulsatile GnRH administration, plasma E2 levels increased, and LH and FSH pulses followed each GnRH pulse during the frequent sampling study. Ovulation occurred in all women during pulsatile GnRH treatment. During Nal 2 treatment, plasma E2 levels returned to prestudy levels without follicular growth, and the pulsatile study was similar to those prior treatment and during Nal 1 administration. In conclusion, Nal, started during priming either with exogenous E2 and P treatment or gonadotropin stimulation induced by pulsatile GnRH administration, was unable when continued alone to initiate or maintain gonadotropin secretion in women with HA. Thus, the exclusive role of opioids in HA and the effect of Nal even in the presence of ovarian steroids are questionable.

Non-responsiveness of serum gonadotropins and testosterone to pulsatile GnRH in hemochromatosis suggesting a pituitary defect.

We investigated the potential pituitary origin of gonadal insufficiency in hemochromatosis. Gonadotropin secretion was studied in seven patients with hemochromatosis and hypogonadism, before and after chronic pulsatile GnRH therapy. Pulsatile LH secretion was studied before (sampling every 10 min for 6 h) and after 15-30 days of chronic pulsatile GnRH therapy (10-12 micrograms per pulse). Prior to GnRH therapy, all the patients had low serum testosterone, FSH and LH levels. LH secretion was non-pulsatile in four patients, while a single pulse was detected in the remaining three. Chronic pulsatile GnRH administration did not increase serum testosterone levels; similarly, serum LH levels remained low: neither pulse frequency nor pulse amplitude was modified. We conclude that hypogonadism in hemochromatosis is due to pituitary lesions.

Progesterone stimulates luteinizing hormone secretion by acting directly on the pituitary.

To determine if progesterone (P) does affect gonadotropin secretion by acting directly on the pituitary, six women with hypothalamic gonadotropin deficiency were studied. They were treated with 17 beta-estradiol (E2; 2 mg/day, orally) to induce P receptors and maintain constant plasma E2 levels during two 15-day periods separated by 1 month. GnRH was administered iv at a dose of 10 microgram/pulse every 90 min during the last 5 days of E2 treatment. Either P (400 mg/day) or a placebo was administered intravaginally in a cross-over randomized design during the 5 days of pulsatile GnRH therapy. A baseline study of pulsatile LH secretion was performed, with sampling performed every 10 min for 8 h. The sampling was then repeated on day 15 of each study period at the end of pulsatile GnRH administration. Plasma levels of E2 and P were measured every day during the 5 days of either GnRH and P or GnRH and placebo treatment. In the six patients, the observed apulsatile pattern of LH during the baseline study confirmed the diagnosis of complete gonadotropin deficiency. Plasma E2 levels were not significantly different at the time of each pulse analysis (288 +/- 61 vs. 252 +/- 77 pmol/L). The plasma P level achieved with the vaginal pessaries was 22 +/- 5 nmol/L. P treatment resulted in all cases in a significant increase in the mean plasma LH level (5.2 +/- 0.9 vs. 3.6 +/- 0.7 IU/L after GnRH plus placebo; P less than 0.001). Furthermore, LH pulse amplitude was significantly increased by P compared to placebo (3.1 +/- 0.3 vs. 1.4 +/- 0.1 IU/L, respectively; P less than 0.01). Mean plasma FSH levels were significantly increased by GnRH regardless of whether P or placebo was present. In conclusion, these data indicate that a short exposure to physiological levels of P in the range of early luteal phase levels has a stimulatory effect on LH secretion by acting directly at the pituitary level.

Effects of a pure antiandrogen on gonadotropin secretion in normal women and in polycystic ovarian disease.

To assess the role of androgens in gonadotropin regulation in women, we studied the effects of a pure nonsteroidal antiandrogen, Anandron (Cassenne, Paris, France). Nine normally cycling women (group 1) with acne and/or seborrhoea and nine patients with polycystic ovarian disease (PCOD) (group 2) received Anandron (100 mg twice a day) and a placebo. Both treatments were administered orally, in a cross-over randomized design, for two consecutive cycles (group 1) or months (group 2) separated by one cycle or 1 month. Luteinizing hormone (LH) pulse frequency and amplitude (cluster analysis), basal and gonadotropin-releasing hormone (GnRH)-stimulated plasma LH/follicle-stimulating hormone (FSH) levels were determined on day 5 of each treatment or placebo cycle. On days 5, 10, 20, and 24 of each cycle or month, plasma estradiol (E2), estrone (E1), testosterone (T), dihydrotestosterone (DHT), androstenedione (A), dehydroepiandrosterone sulfate (DHAS), sex hormone-binding globulin (SHBG) levels, and urinary androstanediol glucuronide (3 alpha-diol G) were measured. Plasma progesterone (P) levels were determined on days 20 and 24 of each cycle (group 1) and on days 5, 10, 20, and 24 (group 2). In both groups, seborrhea and acne decreased markedly within the first month and practically disappeared after 2 months of Anandron treatment. No adverse side effects were reported. None of the normal patients had any disturbance of menstrual cycles as assessed by basal body temperature shift, ultrasonography, and plasma P levels. In PCOD patients, cycles remained anovulatory.(ABSTRACT TRUNCATED AT 250 WORDS)

A rapid method of epitope mapping. Application to the study of immunogenic domains and to the characterization of various forms of rabbit progesterone receptor.

A method is described to map contiguous epitopes recognized by monoclonal antibodies in the case when the cDNA for a protein has been cloned. The cDNA is inserted into an expression vector allowing its acellular transcription, followed by the translation of the resulting messenger RNA. C-terminally truncated species of the protein are either generated by cutting the cDNA with restriction enzymes or arise spontaneously through stops occurring during translation of the mRNA. If necessary, progressive digestion by Bal31 of the cDNA can be used to produce an array of polypeptides having different C-terminal lengths. Immunoprecipitation then allows determination of the shortest protein recognized by the monoclonal antibody and thus to define its site of action. This method has been applied to the study of a group of selected monoclonal antibodies among the 59 that have been prepared against the rabbit progesterone receptor. Four immunogenic domains were identified lying between amino acids 1-60, 101-110, 295-325 and 370-396. There were no antibodies directed against the DNA-binding or the steroid-binding regions of the receptor. This is probably due to the high degree of amino acid sequence conservation in these domains, observed when comparing receptors from different species. The antibodies cross-reacting with highest affinity for the human receptor interact with the first immunogenic domain (amino acids 1-60). The 79-kDa form ('subunit A') of the receptor was shown to lack the two more N-terminally localized immunogenic domains (amino acids 1-60 and 101-110). The 65-kDa form lacked, in addition, the domain localized between amino acids 295 and 325. These two forms of the receptor thus correspond to deletions of the N-terminal part of the protein.

Radioimmunoassay of progesterone receptor in human tissues: application to breast cancer.

A radioimmunoassay method to measure progesterone receptor in rabbit and human tissues was devised and applied to human breast cancer. A specific progesterone receptor antibody was prepared by purifying rabbit receptor by immunoaffinity chromatography, sodium dodecylsulphate-polyacrylamide gel electrophoresis and injection of the isolated 110,000 dalton receptor band into a goat. Immunoblot studies of progesterone target and non-target tissues showed the specificity of the antibody, which was used at a dilution of 1/45,000. The tracer consisted of 125I-labelled electroeluted 110,000 dalton receptor. The sensitivity of the method was 1 fmol/tube for the rabbit receptor and 3 fmol/tube for the human receptor. The intra-assay coefficient of variation was 11% for tumours positive for the progesterone receptor and 9.9% for those on the borderline (10-30 fmol receptor/mg protein). The interassay coefficients of variation were 20 and 19% respectively. The correlation between the radioimmunoassay and a steroid-binding assay was studied in 40 tumour biopsies. In 39 cases, very good correlation was found (r = 0.99); in a single case an immunoreactive protein was detected which apparently bound steroid poorly. One important feature of this method was that receptor immunoreactivity remained unchanged when either the tissue or the cytosol was exposed to a temperature of 20 degrees C for relatively long periods of time. Under the same conditions the steroid-binding capacity declined rapidly. This characteristic of the radioimmunoassay may prevent errors due to improper handling of tissue samples. Such stability was not observed for oestrogen receptors when measured by a sandwich immunoenzymatic method after incubation of tissue at 20 degrees C.

Stimulation of ovarian follicular maturation with pure follicle-stimulating hormone in women with gonadotropin deficiency.

According to the 2-cell theory, ovarian steroidogenesis requires the coordinate action of both FSH and LH. To evaluate the relative importance of these hormones in follicular maturation, a randomized cross-over study was performed in 10 women with complete gonadotropin deficiency (absence of pulsatile LH secretion and no LH response to LHRH). Five women were treated with highly purified FSH (LH bioactivity, 0.09%) and 3 months later with human menopausal gonadotropin (hMG; LH bioactivity, 65%), each given for 10 days at a daily dose of 225 IU FSH, im. The sequence was reversed in the other 5 women. hCG (5000 IU) was administered im 24 h after the last injection of FSH or hMG. Plasma estradiol (E2), estrone (E1), androstenedione (A), testosterone, LH, and FSH concentrations and urinary LH and FSH were measured daily by RIA. Ultrasonography was performed during each treatment and 2 days after each hCG injection. After FSH treatment, mean plasma and urinary FSH levels increased, mean plasma LH did not change, and urinary LH increased slightly but not significantly from 91 +/- 32 (SE) to 164 +/- 55 mIU/24 h (10(-3) IU/24 h). After hMG treatment, mean plasma and urinary LH and FSH levels increased accordingly. The mean basal plasma E2 [11 +/- 1 pg/mL (40 +/- 4 pmol/L)] and E1 [14 +/- 4 pg/mL (52 +/- 15 pmol/L)] levels increased after FSH treatment to 207 +/- 69 pg/mL (760 +/- 253 pmol/L) and 82 +/- 21 pg/mL (303 +/- 78 pmol/L), respectively (P less than 0.01), but plasma A did not change. In response to hMG, the mean plasma E2, E1, A, and testosterone levels increased more than during FSH treatment. Ultrasonography revealed multiple preovulatory follicles (greater than or equal to 16 mm) in 2 women after hMG and 1 woman after FSH treatment; therefore, hCG was not administered. In 3 women given FSH, hCG did not induce ovulation. hCG induced ovulation in 8 women given hMG and in 6 women given FSH, based on ultrasonography and plasma progesterone levels. Thus, in the presence of profound gonadotropin deficiency pharmacological doses of FSH, with minute LH contamination, are capable of stimulating ovarian follicular maturation, underlining the key role of FSH in folliculogenesis.

Characterization of a casein kinase which interacts with the rabbit progesterone receptor. Differences with the in vivo hormone-dependent phosphorylation.

Previous in vivo studies have shown that the rabbit progesterone receptor undergoes two phosphorylation reactions: one basal and a second one which is hormone-dependent. We report here on the presence and characteristics of a kinase activity found in receptor preparations highly purified by immunoaffinity chromatography. 1. This kinase activity is not due to the receptor molecule itself since the two proteins may be separated by several chromatographic and immunological methods. 2. The presence of the kinase in receptor preparations is not an artefact of the purification procedure. The kinase binds to the receptor as shown by coelution in immunoaffinity experiments and during various chromatographies. This interaction probably takes place in vivo and is not artefactually formed during solubilization of the receptor since the kinase also copurifies with receptors isolated from the uterine nuclei of progestin-treated rabbits. 3. This enzyme may be classified as a casein kinase since it readily phosphorylates the latter substrate (Km approximately equal to 0.15 mg/ml) and is not regulated by cyclic nucleotides, Ca2+ and calmodulin or phospholipids. Its classification as a casein kinase I or II is difficult since on the one hand it is inhibited by heparin, activated by polyamines and may use both ATP and GTP, but on the other hand it modifies only serine residues, and is not inhibited by heparin when the receptor itself is employed as a substrate. 4. The kinase which copurifies with the receptor does not mimic in vitro the effects of the hormone-dependent phosphorylation of the receptor observed in vivo: there is no enhancement of kinase activity by the hormone, and the phosphorylated receptor does not exhibit the characteristic "upshift" in its electrophoretic mobility. Thus either this kinase is not the enzyme responsible for the hormone-dependent receptor phosphorylation or, during purification, a factor has been lost which is necessary for retaining the hormone dependency of the reaction.

Comparative effects of cyproterone acetate or a long-acting gonadotropin-releasing hormone agonist in polycystic ovarian disease.

A randomized cross-over study was done to compare the therapeutic efficacy of cyproterone acetate (CPA) and a depot preparation of the LHRH superagonist (DTrp6-LHRH) in 10 patients with polycystic ovarian disease (PCO). All patients were treated with both agents (50 mg/day CPA, orally and (3 mg DTrp6-LHRH, im, approximately once a month) for 3 months, the 2 treatment periods being separated by 6 months. Both treatments resulted in marked clinical improvement, with diminished acne and seborrhoea and normalization of ovarian size by ultrasonographic criteria. In response to CPA treatment, basal plasma gonadotropin levels decreased, but the response to a LHRH test was not completely suppressed. Plasma estradiol, estrone, testosterone, and androstenedione levels significantly decreased, but urinary 3 alpha-androstanediol and plasma dehydroepiandrosterone sulfate levels did not change significantly. In contrast to CPA treatment, both basal and stimulated gonadotropin levels were completely suppressed after 3 weeks of treatment with DTrp6-LHRH. After a slight initial evaluation on day 2, plasma estrogen and androgen levels, with the exception of dehydroepiandrosterone sulfate fell into the castrate range urinary 3 alpha-androstanediol excretion decreased significantly. Thus, in patients with PCO, LHRH-A induced more complete gonadotropin inhibition than did CPA. After cessation of either therapy, the disease rapidly recurred.

Interactions of oestradiol benzoate and promegestone upon basal and TRH-induced prolactin secretion in postmenopausal women.

The interactions of ovarian steroids with PRL secretion in women are still controversial. Ten healthy postmenopausal women, on no medication, received during the first period of 2 months later in a cross-over design study, i.m. injections of 0.625 mg of oestradiol benzoate (EB) alone for 10 d or in combination with 750 micrograms/d of a pure progestin promegestone for 10 d. A TRH (200 micrograms i.v.) stimulation test was performed before the start and at the completion of each treatment period. Basal plasma gonadotrophins, PRL and oestradiol were measured every day by radioimmunoassay. The EB-induced rise in oestradiol levels was similar during the two periods. In response to EB treatment serum PRL levels increased from 6.1 +/- 0.9 ng/ml to 22.9 +/- 3.4 ng/ml. With the addition of promegestone, the increase in PRL, from 6.7 +/- 1.3 ng/ml to 13.8 +/- 2.5 ng/ml, was significantly diminished (P less than 0.001). The PRL release induced by TRH was significantly greater with EB treatment than was the response with the combined treatment (P less than 0.05, Wilcoxon test to compare the areas under the curves). These data suggest that in postmenopausal women oestrogens act as stimulators of PRL release and promegestone is able to partially counteract the stimulatory effect of oestradiol benzoate upon basal and TRH-stimulated PRL secretion.

In vitro and in vivo antagonistic regulation by estradiol and progesterone of the rat pituitary domperidone binding sites: correlation with ovarian steroid regulation of the dopaminergic inhibition of prolactin secretion in vitro.

The influences of in vivo and in vitro estradiol (E2) and progesterone (P) treatments on the characteristics of [3H]domperidone binding to intact and ovariectomized (OVX) rat pituitary membranes were analyzed and compared to the modulation by these steroids of dopamine (DA) inhibition of PRL secretion in vitro from intact and OVX rat pituitaries. Using intact rat pituitaries, high and low affinity binding sites for domperidone were detected; the dose-dependent DA inhibition curve of PRL secretion was biphasic (range, 10(-13) - 10(-10) M DA, IC50 = 6 X 10(-12) M; range, 10(-10) - 10(-6) M DA, IC50 = 2 X 10(-8) M). Using OVX rat pituitaries, only the high affinity sites for domperidone were detected, and the dose-dependent DA inhibition curve of PRL secretion was monophasic (range, 10(-10) - 10(-6) M DA, IC50 = 10(-8) M). E2 and P did not modify the characteristics of the high affinity sites either after in vivo treatment or when directly added to the in vitro binding assay. However, using in vivo and in vitro tests, a modulation of the low affinity sites by E2 and P was demonstrated. When E2 is in excess and P levels are low or undetectable, these sites are not detectable, and P is able to restore there presence. A parallelism has been established between this antagonistic E2 and P regulation and the modulation of DA inhibition of PRL secretion (range, 10(-13) - 10(-10) M DA). When intact rat pituitaries are perifused in the presence of 10(-8) M E2, the biphasic dose-dependent inhibition curve of the control is changed into the monophasic curve of the OVX rat pituitaries. Conversely, when OVX rat pituitaries are perifused in the presence of 10(-6) M P, the monophasic curve of the control is changed into the biphasic curve of the intact rat pituitaries. Thus, the DA inhibition in the range 10(-13) - 10(-10) M might result from an interaction between DA and the low affinity site for domperidone. In summary, the biological regulation of PRL by DA at the pituitary level may be mediated by two different DA sites, one being submitted to an antagonistic E2 and P regulation directly at the membrane level. The consequence of this regulation is that, whereas E2 decreases the sensitivity of the cell to DA, P is necessary for a normal DA response of the lactotroph.