Effects of thyrotropin, follicle stimulating hormone and luteinizing hormone on sIL-2R in vitro secretion from human peripheral blood mononuclear cells

The effect of thyroid stimulating hormone (TSH) or thyrotropin (0.06, 0.6, 6, and 60 microIU/ml), follicle stimulating hormone (FSH) and luteinizing hormone (0.1, 1, 10, and 100 mIU/ml) on soluble interleukin-2 receptor (sIL-2R) release in vitro from resting or phytohaemagglutinin (PHA) activated human peripheral blood mononuclear cells (PBMC) was evaluated. sIL-2R concentrations were measured in supernatants of cultured cells by quantitative sandwich enzyme immunoassay method (ELISA). TSH in a dilution of 0.6 microIU/ml and FSH in a concentration of 1 mIU/ml inhibited the secretion of sIL-2R only (p < 0.01) into supernatants from PHA activated PBMC cultures.     

Influence of serum, estrogen, and gonadotropins upon growth and progesterone secretion by cultures of granulosa cells from small porcine follicles

Granulosa cells from small (less than 2mm) antral porcine follicles were grown in culture to study the effects of various hormones on growth, morphology and progesterone secretion. Culture medium 199D + 4% serum was found to be most suitable since it maintained a fairly constant cell population. Estradiol (1mug/ml) and human FSH stimulated cell growth. LH and FSH stimulated progesterone secretion and induced morphological changes associated with luteinization. Estradiol (0.1 mug/ml) inhibited progesterone secretion by granulosa cells.     

Effects of growth hormone, prolactin, insulin-like growth factors, and gonadotropins on progesterone secretion by porcine luteal cells

Growth hormone (GH) and IGF-I have receptors within the corpus luteum (CL) and stimulate CL function. Our objective was to investigate the effects of GH, prolactin (PRL), IGF-I, IGF-II, LH, and FSH on progesterone secretion by porcine luteal cells during mid-pregnancy. Gilts (crossbred Yorkshire/Landrace) were slaughtered on d 44 of pregnancy and CL were collected. Large and small luteal cells (LLC and SLC, respectively) were obtained from dissociated CL and separated by elutriation. Luteal cells were incubated with 0, 1, 10, or 100 ng/mL of GH, PRL, IGF-I, IGF-II, LH, and FSH or combinations of 10 ng/mL of these reagents for 24 or 48 h. Culture media were harvested and concentrations of progesterone analyzed by radioimmunoassay. Growth hormone, PRL, and IGF-I increased (P < .05; 100 ng/mL dose) concentrations of progesterone in media of LLC. Insulin-like growth factor-II, LH, and FSH had no effect on progesterone in LLC cultures. In SLC cultures, GH, PRL, IGF-I, IGF-II, and FSH failed to stimulate progesterone secretion, whereas LH increased progesterone secretion (linear effect of dose; P < .05). Combinations (10 ng/mL each hormone) of GH and IGF-I or PRL and IGF-I increased progesterone secretion by LLC compared with control, GH, PRL, or IGF-I alone (P < .05). Similar combinations of GH or PRL with IGF-I had no effect on SLC. Conclusions are that GH and PRL are stimulatory to progesterone secretion by LLC (location of GH receptor) and SLC are responsive to LH during mid-pregnancy. Both GH and PRL are synergistic with IGF-I for increased progesterone secretion.     

Prostaglandin F and progesterone secretion by porcine endometrium and corpus luteum in vitro

Slices of porcine endometrium and corpus luteum tissue obtained from mature sows throughout the luteal phase of the oestrous cycle were incubated in culture medium which was analysed at regular intervals over a period of 8 hours for prostaglandin F and progesterone. Prostaglandin F secretion was greatest by endometrium obtained during the mid III to late I luteal stage of the cycle and the increased levels secreted by this tissue were paralleled by high levels of secretion from corpus luteum tissue. The addition of indomethacin (10 mug/ml) to the culture medium completely abolished prostaglandin F secretion by both endometrium and luteal tissue indicating that the high levels of the prostaglandin were due to synthesis. Progesterone secretion by the corpus luteum was maximal from early luteal tissue and had declined to considerably lower levels by late stage tissue when prostaglandin secretion was greatest. The possible physiological significance of luteal prostaglandin F secretion is discussed.     

Developmental potential of embryos produced by in-vitro fertilization from gonadotrophin-releasing hormone antagonist-treated macaques stimulated with recombinant human follicle stimulating hormone alone or in combination with luteinizing hormone

We previously demonstrated, in luteinizing hormone (LH)-deficient macaques, that follicular growth and maturation occurred with administration of exogenous (recombinant human) follicle stimulating hormone (r-hFSH) alone, and that the oocytes recovered fertilized at a notably higher rate than their counterparts from animals receiving both r-hFSH and r-hLH (Zelinski-Wooten et al., 1995). Here, the developmental potential of embryos produced from animals treated with r-hFSH alone or in combination with r-hLH was evaluated. Embryos (n = 127) were cryopreserved, thawed and either co-cultured on buffalo rat liver cells until the hatched blastocyst stage or transferred to synchronized recipients. Although embryos from each treatment group demonstrated a similar ability to develop to hatched blastocysts with a definitive inner cell mass, a significant difference was seen in cryosurvival (56 versus 78%) and in developmental rate to the hatched blastocyst (12 versus 10 days) between embryos from the r-hFSH alone and the combination group respectively. Pregnancies resulted following oviductal embryo transfers in both groups, with corpus luteum rescue occurring on days 12-16 of the luteal phase. In summary, r-hFSH alone during the pre-ovulatory interval is adequate for the gametogenic events required to produce embryos that develop either in vitro or in vivo; however, exposure to r-hLH may improve embryo viability and the rate of development.     

Development of human primordial follicles to antral stages in SCID/hpg mice stimulated with follicle stimulating hormone

In contrast to the many detailed studies of Graafian follicles, the biology of small follicles in the human ovary is poorly understood and the trigger for follicular growth initiation remains unknown. No practical model exists to study preantral follicle growth in the human because of their slow growth rate and lack of an effective culture system. We therefore tested ovarian xenografts as a new strategy to study the early stages of ovarian follicular growth in vivo. Mice homozygous for severe combined immunodeficiency (SCID) and hypogonadism (hpg) received human ovarian xenografts under their kidney capsules. Follicle growth was assessed by morphology and proliferating cell nuclear antigen (PCNA) immunostaining. The grafts were recovered after 11 (short-term) and 17 weeks (long-term), and serially sectioned. During the last 6 weeks of long-term grafting, mice were randomized to receive either placebo or 1 IU of purified follicle stimulating hormone (FSH) s.c. on alternating days. After 11 weeks of grafting, the most advanced follicles had a maximum of two granulosa cell layers. In the absence of FSH administration, follicles did not progress beyond the two-layer stage even after 17 weeks of grafting, and the oestradiol levels remained undetectable. In the FSH-treated long-term grafts, follicles had grown to antral stages and resulted in oestradiol levels as high as 2070 pmol/l. Growth initiation indices did not differ between control and FSH-treated grafts. This study demonstrates that follicles can survive and grow in human ovarian tissue grafted under the renal capsules of immunodeficient mice for at least 17 weeks, and indicate that xenograft models are potentially useful for studying human follicle development. Using this physiological model, we showed that FSH is required for follicle growth beyond the two-layer stage, although growth initiation is independent of gonadotrophin stimulation.     

Thyroid hormone inhibits aromatase activity in porcine thecal cells cultured alone and in coculture with granulosa cells

We cultured porcine thecal and granulosa cells alone or in coculture to define whether thyroid hormone affects aromatase activity in porcine ovarian cells. Dispersed cells were cultured with 10(-9) M triiodothyronine (T3) for 24 hours. Testosterone (final concentration 10(-7) M) was added as aromatase substrate for granulosa cells (Gc) cultured alone. Thecal (Th) androgens serve as a substrate for estradiol secretion by Th cells cultured alone and in coculture with Gc. At the end of the preincubation time, the culture media was removed and replaced with fresh media containing 100 ng follicle stimulating hormone (FSH) or 10(-3) M 8-bromo-cyclic adenosine monophosphate (8-Br-cAMP). After overnight incubation, the culture media was analyzed for estradiol production by radioimmunoassay (RIA). T3 inhibited basal, FSH-stimulated, and 8brcAMP-stimulated estradiol production in all culture conditions. T3 inhibited cAMP analogue 8-Br-cAMP and FSH-induced aromatase activity to a similar extent, thus suggesting that the inhibitory effect of T3 is downstream of cAMP formation. In the second part of the experiment a rabbit polyclonal antibody against human placental cytochrome P-450arom was used to confirm the effect of T3 on aromatase protein in Th and Gc. Pretreatment of Th and Gc with T3 markedly decreased immunostaining for aromatase in both types of cells, suggesting a direct effect of T3 on this enzyme.     

Effects of profound suppression of luteinizing hormone during ovarian stimulation on follicular activity, oocyte and embryo function in cycles stimulated with purified follicle stimulating hormone

The effects of profound suppression of circulating luteinizing hormone (LH) during the follicular phase of in-vitro fertilization cycles were explored in normal women during treatment with a gonadotrophin-releasing hormone analogue and exogenous purified follicle stimulating hormone. Ovarian responses to treatment and the capacity of supernumerary embryos to undergo blastocyst formation were examined in groups of patients defined by the concentration of plasma LH in the mid-follicular phase. Concentrations < or = 0.5 IU/I diagnosed the group with profoundly suppressed LH (相似文献   

Effect of estradiol-17 beta on basal and hCG stimulated progesterone secretion by porcine luteal cells isolated in various stages of the luteal phase

T cells of mice display V beta-specific reactivity for a spectrum of mouse mammary tumor virus (Mtv) antigens; confrontation with these antigens during ontogeny causes substantial "holes" in the T cell repertoire. Since endogenous Mtv antigens are rare in other species, the question arises whether V beta-specific recognition of Mtv antigens is unique to mice. To examine this question, rat T cells were allowed to differentiate from stem cells in severe combined immunodeficiency (SCID) mice. These rat-->mouse xenochimeras were prepared under a variety of conditions. The results show that rat T cells are strongly reactive to mouse Mtv antigens, both in terms of tolerogenicity and immunogenicity. In fact, the V beta specificity of rat and mouse T cells for Mtv antigens is almost indistinguishable.     

Regulation of oxytocin, oestradiol and progesterone receptor concentrations in different uterine regions by oestradiol, progesterone and oxytocin in ovariectomized ewes

The regulation of oxytocin, oestradiol and progesterone receptors in different uterine cell types was studied in ovariectomized ewes. Animals were pretreated with a progestogen sponge for 10 days followed by 2 days of high-dose oestradiol to simulate oestrus. They then received either low-dose oestradiol (Group E), low-dose oestradiol plus progesterone (Group P) or low-dose oestradiol, progesterone and oxytocin (via osmotic minipump; Group OT). Animals (three to six per time-point) were killed following ovariectomy (Group OVX), at oestrus (Group O) or following 8, 10, 12 or 14 days of E, P or OT treatment. In a final group, oxytocin was withdrawn on day 12 and ewes were killed on day 14 (Group OTW). Oxytocin receptor concentrations and localization in the endometrium and myometrium were measured by radioreceptor assay, in situ hybridization and autoradiography with the iodinated oxytocin receptor antagonist d(CH2)5[Tyr(Me)2,Thr4,Tyr-NH2(9)]-vasotocin. Oestradiol and progesterone receptors were localized by immunocytochemistry. Oxytocin receptors were present in the luminal epithelium and superficial glands of ovariectomized ewes. In Group O, endometrial oxytocin receptor concentrations were high (1346 +/- 379 fmol [3H]oxytocin bound mg protein-1) and receptors were also located in the deep glands and caruncular stroma in a pattern resembling that found at natural oestrus. Continuing low-dose oestradiol was unable to sustain high endometrial oxytocin receptor concentrations with values decreasing significantly to 140 +/- 20 fmol mg protein-1 (P < 0.01), localized to the luminal epithelium and caruncular stroma but not the glands. Progesterone treatment initially abolished all oxytocin receptors with none present on days 8 or 10. They reappeared in the luminal epithelium only between days 12 and 14 to give an overall concentration of 306 +/- 50 fmol mg protein-1. Oxytocin treatment caused a small increase in oxytocin receptor concentration in the luminal epithelium on days 8 and 10 (20 +/- 4 in Group P and 107 +/- 35 fmol mg protein-1 in Group OT, P < 0.01) but the rise on day 14 was not affected (267 +/- 82 in Group OT and 411 +/- 120 fmol mg protein-1 in Group OTW). In contrast, oestradiol treatment was able to sustain myometrial oxytocin receptors (635 +/- 277 fmol mg protein-1 in Group O and 255 +/- 36 in Group E) and there was no increase over time in Groups P, OT and OTW with values of 61 +/- 18, 88 +/- 53 and 114 +/- 76 fmol mg protein-1 respectively (combined values for days 8-14). Oestradiol receptor concentrations were high in all uterine regions in Group O. This pattern and concentration was maintained in Group E. In all progesterone-treated ewes, oestradiol receptor concentrations were lower in all regions at all time-points. The only time-related change occurred in the luminal epithelium in which oestradiol receptors were undetectable on day 8 but developed by day 10 of progesterone treatment. Progesterone receptors were present at moderate concentrations in the deep glands, caruncular stroma, deep stroma and myometrium in Group O. Oestradiol increased progesterone receptors in the luminal epithelium, superficial glands, deep stroma and myometrium. Progesterone caused the loss of its own receptor from the luminal epithelium and superficial glands and decreased its receptor concentration in the deep stroma and myometrium at all time-points. There was a time-related loss of progesterone receptors from the deep glands of progesterone-treated ewes between days 8 and 14. These results show differences in the regulation of receptors between uterine regions. In particular loss of the negative inhibition by progesterone on the oxytocin receptor by day 14 occurred only in the luminal epithelium, but is unlikely to be a direct effect of progesterone as no progesterone receptors were present on luminal epithelial cells between days 8 and 14.     

Evidence suggesting an additional control mechanism regulating episodic secretion of luteinizing hormone and follicle stimulating hormone in pre-pubertal children and post-menopausal women

The possible differential regulation of pulsatile follicle stimulating hormone (FSH) and luteinizing hormone (LH) secretion in pre-pubertal children and in post-menopausal women was investigated. Children were studied for 4 h and post-menopausal women for 6 h; blood samples were taken every 10 min. Post-menopausal women were studied before and 21 days after administration of a single i.m. dose of gonadotrophin-releasing hormone (GnRH) analogue. Eight post-menopausal women and 18 children (nine boys and nine girls) were enrolled. The children were divided into two groups: A, at Tanner stages 0-1 (four boys and three girls); B, at Tanner stage 2-3 (five boys and six girls). Plasma LH and FSH concentrations were determined using an immunofluorimetric assay. Time series were analysed and the specific concordance (SC) index was computed to determine the degree of concordance between episodes of LH and FSH secretion. While children of group A had LH concentrations below the minimal detectable dose of 0.1 IU/l, group B showed measurable LH plasma concentrations (1.4 +/- 0.3 IU/l, mean +/- SEM). Plasma FSH concentrations were detectable in both groups. Group A showed FSH plasma concentrations significantly lower than those of group B (0.75 +/- 0.2 and 1.95 +/- 0.4 IU/l respectively; P < 0.05), but FSH pulse frequency was higher in group A (P < 0.05). Children of group B showed significant concomitance of LH and FSH secretory events at time 0 (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Regulation of the activin-binding protein follistatin cultured human luteinizing granulosa cells: characterization of the effects of follicle stimulating hormone, prostaglandin E2, and different growth factors

Regulation of the activin-binding protein follistatin (FS) by recombinant human (rh) FSH, prostaglandin E2 (PGE2), and several polypeptide growth factors was examined in cultures of human granulosa-luteal (GL) cells obtained from in-vitro fertilization patients at oocyte retrieval. Northern and dot blot hybridization analyses demonstrated that both rhFSH and PGE2 caused stimulatory effects on FS mRNA levels in a culture stage-, time-, and concentration-dependent manner. An 8-h stimulation with rhFSH (100 ng/ml) significantly increased FS mRNA levels on Days 5 and 7 of culture and PGE2 (10(-6)M) on Days 2, 4, and 7. The stimulatory effect of rhFSH and PGE2 on FS mRNA levels were rapid and transient. Maximal inductions occurred 8 h after stimulation, whereas weak or no stimulatory effects were seen at 24 or 48 h. PGF2 alpha did not affect FS mRNA levels at any time point studied. Treatment of the cells with the protein synthesis inhibitor cycloheximide prior to rhFSH stimulation did not inhibit the rapid induction of FS mRNAs, but it prevented the decline at 24 h. Both rhFSH and PGE2 clearly also increased the levels of secreted FS proteins are detected by immunoprecipitation studies with a specific antibody. The effects of the polypeptide growth factors epidermal growth factor (EGF); transforming growth factor beta 1 (TGF beta 1), and activin A on FS mRNA levels were also examined. TGF beta 1 and activin A had no effect on basal FS expression at any concentration or time point studied. An 8-h stimulation with EGF increased FS mRNA levels, but the effect was weaker than those caused by rhFSH and PGE2. We conclude that rhFSH and PGE2 induce FS mRNA and protein in human cultured GL cells. EGF is able to induce FS mRNA to a lesser extent than are rhFSH and PGE2, whereas PGF2 alpha, TGF beta 1, and activin A do not affect basal FS mRNA levels in human cultured GL cells. This study together with our previous report on the stimulatory effect of hCG on FS levels suggest that in the luteal phase of the human menstrual cycle, FS expression in granulosa cells is likely to be positively controlled by luteotropic factors such as gonadotropins and PGE2. Consequently, elevated FS levels may support the survival of the human CL since FS is known to prevent the antisteroidogenic effects of activin in human GL cells.     

Effect of growth hormone administration on circulating levels of luteinizing hormone, follicle stimulating hormone and testosterone in normal healthy men

A new area of growth hormone (GH) therapy in adults is the treatment of infertility. The aim of this study was to evaluate the effects of pharmacological GH administration on the secretion of pituitary and gonadal hormones in normal men. Eight healthy men, 23-32 years of age (mean 28.1 years), with a normal body mass index were studied in a double-blind, placebo-controlled crossover design. All participants had a normal semen analysis before entering the study. Each participant was treated with placebo and GH (12/IU/day, Norditropin; Novo Nordisk, Denmark) during two different 14-day periods, separated by a 6 week washout period. Administration of GH for 14 days resulted in a significant increase in serum insulin-like growth factor I (IGF-I; P < 0.01) but no changes occurred in IGF-I values during placebo treatment. The concentrations of follicle stimulating hormone and luteinizing hormone displayed no change during the two periods and did not differ between the GH treatment period and the placebo period. The concentration of testosterone was unchanged during the placebo/GH periods and there was no difference between the GH treatment period and the placebo period. We conclude that GH treatment for 14 days in normal healthy men does not affect gonadotrophin or testosterone patterns.     

Differential modulation of porcine theca, granulosa, and luteal cell steroidogenesis in vitro by tumor necrosis factor

The role of tumor necrosis factor alpha (TNF alpha) in ovarian function was investigated using in vitro culture of theca and granulosa cells isolated from gilt follicles (4-6 mm) and small (SLC) and large (LLC) luteal cells from mid-cycle corpora lutea. TNF alpha did not affect basal accumulation of progesterone (P) by theca cells after 72 h of culture. However, TNF alpha (0.1-100 ng/ml) caused a marked dose-dependent noncytotoxic inhibition (p < 0.05) of LH or LH+insulin (I)-stimulated P accumulation by theca cells after 72 h. Maximal inhibitions averaged 87 +/- 6% at 5 ng/ml TNF alpha for LH-stimulated P and 69 +/- 4% at 50 ng/ml TNF alpha for LH+I-stimulated P. The inhibitory effect of TNF alpha, evident by 24 h after culture, progressively increased on Days 2 and 3 of culture. The effect of TNF alpha on theca cells was mediated by cAMP generation as evidenced by TNF alpha inhibition of LH-induced cAMP accumulation and P accumulation in response to LH and forskolin but not dibutyryl cAMP. Consistent was this, TNF alpha had no effect on increased P accumulation by theca cells in the presence of 22-hydroxycholesterol or pregnenolone alone, but inhibited further increases in P accumulation stimulated by LH plus sterol substrates. Unlike that in theca cells, FSH-induced P accumulation in granulosa cell cultures was slightly enhanced (p < 0.05) by low doses of TNF alpha (0.1, 0.5, and 1.0 ng/ml) after 72 h, while higher doses (5-50 ng/ml) did not alter P accumulation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Triiodothyronine (T3) modulates hCG-regulated progesterone secretion, cAMP accumulation and DNA content in cultured human luteinized granulosa cells

Ample clinical evidence indicates that women with thyroid disorders frequently exhibit menstrual disturbances and impaired fertility. In order to characterize the nature of thyroid hormone action in the ovary, the direct effects of triiodothyronine (T3) were investigated in vitro using a culture system of human luteinized granulosa cells. The presence of T3 receptors was also searched in such cells. The cell cultures were maintained in serum-free Ham's F-10 medium in the absence or presence of hCG, with or without graded doses of T3 (10(-11)-10(-7) M), and cell proliferation (assessed by DNA content) as well as cell function (cAMP accumulation and progesterone secretion) determined. T3 alone stimulated cell proliferation. hCG, on the other hand, was anti-mitogenic and T3 combined with hCG inhibited cell growth even further, reaching levels below those reached by either control or hCG alone. Exposure of cells to T3 markedly enhanced hCG-induced cAMP accumulation. Addition of 1-methyl-3-isobutylxanthine (MIX) abolished the cAMP-stimulatory effect elicited by T3, suggesting that the thyroid hormone may act, as MIX, by inhibiting phosphodiesterase. T3 was devoid of any influence on basal progesterone secretion, but inhibited hCG-induced secretion of the steroid. The effects of T3 are not accounted for by changes in cell number since the influence of thyroid hormone on cAMP and steroid secretion were expressed per microgram DNA.(ABSTRACT TRUNCATED AT 250 WORDS)     

Purified urinary follicle stimulating hormone induces different hormone profiles compared with menotrophins, dependent upon the route of administration and endogenous luteinizing hormone activity

The effects of treatment of patients with gonadotrophin-releasing hormone analogue (GnRHa) combined with purified follicle stimulating hormone (FSH) for in-vitro fertilization (IVF) were investigated in detail to determine the influences of different administration routes and the degree of suppression of luteinizing hormone (LH). Responses to exogenous gonadotrophins were studied in infertile women (n = 60) with normal menstrual rhythm whose endogenous gonadotrophin activity was suppressed using a GnRHa in a long protocol. They were randomized to receive i.m. administration of human menopausal gonadotrophins (HMGim, Pergonal) or purified follicle stimulating hormone (FSH, Metrodin High Purity) administered either i.m. (MHPim) or s.c. (MHPsc). Responses were assessed by measuring plasma FSH, LH, oestradiol, testosterone and progesterone. After stimulation day 4, the MHPsc group showed significantly higher circulating concentrations of FSH than either the MHPim or HMGim group. However, the HMG group showed significantly higher oestradiol concentrations after stimulation day 5 than either MHP group. The differences in circulating oestradiol concentrations in the MHP-treated patients appeared to be strongly influenced by the mean circulating concentrations of LH in the follicular phase. The patients who showed mean follicular phase LH concentrations of < 1 IU/l showed longer follicular phases, lower circulating oestradiol and testosterone concentrations and also lower follicular fluid concentrations of oestradiol and testosterone, indicating a reduction in the normal follicular metabolism of progesterone to androgens and oestrogens under these conditions. This group of patients also showed longer follicular phases, which may have consequences for future clinical management.     

Differential responses of granulosa cells from small and large follicles to follicle stimulating hormone (FSH) during the menstrual cycle and acyclicity: effects of tumour necrosis factor-alpha

This study determined effects of follicle stimulating hormone (FSH) alone and in combination with tumour necrosis factor (TNF), on granulosa cells from small (5-10 mm diameter) and large (>10-25 mm) follicles during follicular and luteal phases of the cycle and during periods of acyclicity. Granulosa cells were collected from ovaries of premenopausal women undergoing oophorectomy. The cells were cultured with human FSH (2 ng/ml) and testosterone (1 microM) in the presence or absence of human TNF-alpha (20 ng/ml). Media were removed at 48 and 96 h after culture and progesterone, oestradiol and cAMP in media were measured by radioimmunoassays. FSH stimulated the accumulation of oestradiol from granulosa cells of small follicles during the follicular and luteal phases but not during acyclicity; and TNF reduced oestradiol accumulation in the presence of FSH. Interestingly, in granulosa cells from small follicles, progesterone and cAMP secretion increased in response to FSH and neither was affected by TNF. Thus, TNF specifically inhibited the conversion of testosterone to oestradiol in granulosa cells from small follicles. FSH stimulated oestradiol production by granulosa cells of large follicles obtained only during the follicular phase of the cycle and TNF inhibited the FSH-induced oestradiol secretion. Granulosa cells obtained from large follicles during the luteal phase and during acyclicity did not accumulate oestradiol in response to FSH. However, FSH increased progesterone and cAMP secretion by granulosa cells obtained from large follicles during the follicular and luteal phases. During the luteal phase alone, TNF in combination with FSH increased progesterone accumulation above that of FSH alone. FSH did not increase progesterone, oestradiol or cAMP secretion by granulosa cells obtained from large follicles during acyclicity. Thus, FSH increases progesterone, oestradiol and cAMP secretion by granulosa cells of small follicles during the follicular and luteal phases and TNF appears to inhibit FSH-induced oestradiol secretion specifically in those cells. In large follicles, FSH-stimulated granulosa cell secretion of oestradiol is limited to the follicular phase and this effect can be inhibited by TNF. In addition, when granulosa cells of large follicles do not increase oestradiol secretion in response to FSH, TNF stimulates progesterone secretion.     

Leptin concentrations in the follicular phase of spontaneous cycles and cycles superovulated with follicle stimulating hormone

It has been reported that oestradiol may play a role in the production of leptin from adipocytes. To investigate this relationship further, nine normally ovulating women were studied during two menstrual cycles, i.e. an untreated spontaneous cycle and a cycle treated with follicle stimulating hormone (FSH) from cycle day 2 until the day of human chorionic gonadotrophin (HCG) injection. Serum leptin values on cycle day 2 did not differ significantly between the spontaneous and the FSH cycles. In the spontaneous cycles, leptin values declined gradually and significantly up to day 7 and then increased progressively up to the day of luteinizing hormone (LH) surge onset, at which point they achieved the highest values. In the FSH cycles, serum leptin values increased gradually and significantly up to day 6, remaining stable thereafter, and were in the midfollicular phase significantly higher than in the spontaneous cycles. Significant positive correlations were found between mean values of leptin and mean values of oestradiol during the second half of the follicular phase in the spontaneous cycles and during the first half in the FSH cycles. A significant negative correlation was found between these two parameters in the spontaneous cycles during the first half of the follicular phase. Serum leptin levels were significantly higher in the midluteal than in the follicular phase in both cycles. These results demonstrate for the first time significant changes in leptin values during the follicular phase of the human menstrual cycle and a significant increase during superovulation induction with FSH. It is suggested that oestradiol may be involved in the regulation of leptin production in women.     

Steroid productions by co-cultures of granulosa cells with inner and outer theca cells in preovulatory follicles of gonadotropin stimulated calves

Granulosa, interna and externa theca cells were isolated from large follicles of equine-chorionic-gonadotropin (eCG)-primed calves and co-cultured during 3 days in the absence or in the presence of dehydroepiandrosterone (DHEA). Co-cultures were performed by adding defined numbers of theca and/or granulosa cells which represented 0, 10, 20, 50 or 100% of total cells per well. Secretion of oestradiol-17beta (E2), androstenedione (A4) and progesterone (P4) depended on the type of theca cells (P < 0.001), on the percentage of seeded granulosa cells (P < 0.001) and on the day of culture (P < 0.001). DHEA increased (P < 0.001) E2 and A4, but not P4 (P > 0.05) productions. Interactions existed between these factors (P < 0.01). On day 1, A4 production was nil in granulosa cells alone. E2 production was negligible in theca cells alone but it increased when granulosa cells were added. E2 and A4 varied in an opposite manner according to the percentage of granulosa cells and with the type of theca cells. On day 3, without DHEA, E2 and A4 were low. On day 3 with DHEA, E2 production was maintained in granulosa cells alone but not with any combination of theca cells. In these conditions, A4 production was maintained in the presence of theca cells but not in granulosa cells alone. Granulosa cells alone secreted more P4 than theca cells. P4 increased as a function of the percentage of granulosa in co-cultures with externa but not interna theca cells with which it remained low. In conclusion, theca cells in culture have two effects in relation to the granulosa cells, which differ according to the steroid concerned and to the cell combination. Both types of theca cells have an inhibitory effect on E2 secretion whereas only interna theca cells are able to alter P4 production.