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PubMed1993

Serotonin secretion from rat Leydig cells.

In rat Leydig cells, serotonin (5HT) binds to 5HT2 receptors and stimulates the secretion of CRF which in turn acts as an inhibitor of gonadotropin-induced cAMP formation and androgen production. In the present study we defined the regulation of 5HT secretion in cultured Leydig cells. Adult Leydig cells secreted considerable quantities of 5HT (100-150 pg/10(6) cells per 10 min). The release of 5HT was acutely stimulated by hCG (ED50, 1.1 pM) with maximal stimulation at 10 pM hCG (160%). Forskolin also increased (+220%) 5HT release from cultures (ED50, 50 nM) while TPA was much less effective (+20%), indicating a major role for cAMP in gonadotropin-induced 5HT release. This was confirmed by the finding that 8-Br cAMP (1 mM) was an effective stimulus of 5HT release (+360%). Similar increases of 5HT release by hCG were observed in the absence of extracellular Ca2+. However, ionomycin was a potent stimulus of 5HT release, indicating that elevation of cytoplasmic [Ca2+] could also induce amine secretion. The 5HT content of Leydig cells ranged from 300 to 350 pg/10(6) cells, and decreased during stimulation of 5HT release. Also, immunohistochemical studies revealed specific staining of 5 HT in interstitial cells of the adult rat testis. These studies demonstrated that rat Leydig cells contain and secrete 5HT, and that 5HT release is stimulated by gonadotropin acting primarily through a cAMP-mediated mechanism.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1994

Stimulatory and inhibitory factors of Leydig cell steroidogenesis are secreted simultaneously by the rat seminiferous tubules and do not affect Leydig cell inhibin production in vitro.

The effect of conditioned medium from rat seminiferous tubules (at Stages VII-VIII and Stages IX-VI) cultured with or without follicle-stimulating hormone (FSH) on the production of testosterone and immunoactive inhibin by Leydig cells was examined. Low doses of conditioned medium from unstimulated tubules at Stages VII-VIII significantly (P < 0.05) increased the mean testosterone production to greater than 31 +/- 11% over that achieved with luteinizing hormone (LH) alone. At the highest dose, the conditioned medium significantly inhibited (P < 0.05) LH-stimulated testosterone production by 13 +/- 7%. Low doses of conditioned medium from unstimulated tubules at Stages IX-VI increased the mean testosterone production to 22 +/- 10%, whereas at higher doses, a significant reversal in the stimulation occurred although not to the same extent as that found with medium from tubules at Stages VII-VIII. Conditioned medium from FSH-stimulated tubules at Stages VII-VIII and Stages IX-VI, significantly increased testosterone production to 39 +/- 7% and 31 +/- 13% respectively. Immunoactive inhibin production by the Leydig cells remained unaffected by exposure to conditioned medium from FSH stimulated and unstimulated tubules at Stages VII-VIII and Stages IX-VI. The data demonstrate that tubule culture medium contains FSH-modulated activities which can specifically stimulate and inhibit testosterone synthesis by adult rat Leydig cells in vitro and therefore explains the contradictory reports in the literature.

Animals↗
PubMedDate not supplied

Effect of beta adrenergic antagonist on the production of testosterone by rat's Leydig cells.

BACKGROUND: The Leydig cell is the source of the male sex steroids, or androgens, which are essential for the maintenance of the male phenotype, the male gonads. and spermatogenesis. It has been reported that patients taking beta-blockers experience sexual dysfunction. The purpose of this study was to explore the direct mechanism by which beta adrenergic antagonist exert its' effect on testosterone production by rat Leydig cells. METHODS: Enzymatic dispersion of rat Leydig cell was done. About 85000 cells per tube were taken. After removal of endogenous testosterone by preincubation, The rat Leydig cells were incubated with varying concentrations of Atenolol: [Selective Beta-Adrenergic Antagonist] (10(-6), 10(-7) and 10(-9) M) with or with out LH 250 IU for three hours to measure the testosterone release by RIA. RESULTS: Atenolol, in varying concentrations caused a significant (P<0.05) reduction in testosterone release by the rat Leydig cells as compared to the basal release of testosterone in a dose-dependent fashion. Atenolol decreased the testosterone release by LH stimulated Leydig cells more significantly (P<0.001) as compared to the effects of Atenolol produced on non-stimulated Leydig cells. CONCLUSION: The current data indirectly suggest that Atenolol inhibits testosterone releasee via mechanism involving decrease production of cAMP but not affecting the enzyme activities of steroidogenesis.

Adrenergic Antagonists↗
PubMed2005

Minimal activity in both proliferation and apoptosis of interstitial cells indicates seasonally persisting Leydig cell population in roe deer.

Seasonally regulated breeding is associated with significant changes in testis mass, structure and function. This includes the variation in size, structure and function of the Leydig cells. Recently, interstitial cells have been characterised as a numerically constant population in roe deer. However, no consistent data are available regarding changes in the number of Leydig cells, their differentiation or turnover in seasonally breeding mammals. This study has quantified the numbers of both proliferating and apoptotic cells in roe deer testis bimonthly during a complete annual cycle. Proliferation was detected by immunolocalisation of PCNA and Ki-67 in tissue sections, whereas apoptosis was localised by the TUNEL technique and an antibody to caspase-3. The labelled cells were counted by using a computer-aided image-analysing system. The number of proliferating spermatogenic cells per tubule cross section showed seasonal changes with a maximum in April (14.9+/-0.6) and a subsequent decline up to December (1.6+/-0.3). Percentages of positive cells per square millimetre of interstitial area were below 1% throughout the year. The average number of apoptotic cells per tubule cross section was low and varied only between 0.5 and 1.4 (caspase-3) or 0.1 and 2.1 (TUNEL). In the interstitial compartment, only a few apoptotic cells (<or=0.7%) were found sporadically scattered within the intertubular region during all studied seasonal periods. The results suggest that a constant total number of interstitial cells arise from a conserved cell population of changing functional state rather than from a steady-state population with a definite turnover of cells during seasonal changes in testicular activity.

Animals↗
PubMed1988

A factor(s) produced by Sertoli cells stimulates androgen biosynthesis by Leydig cells in neonatal rats.

Using a coculture system, we have studied the local action of Sertoli cells on Leydig cell function. The results show that (i) both LH and FSH have equal potency to stimulate testosterone biosynthesis by fetal and neonatal testicular cells in an age-dependent manner, the maximum stimulation is observed between D3 and D5. (ii) An FSH-dependent factor(s) secreted by Sertoli cells increases the basal and/or LH-stimulated Leydig cell androgen production. (iii) The Sertoli cell-stimulating factor(s) is not a steroid or other small molecule, but a heat-labile peptide.

Animals↗
PubMed1997

Src tyrosine kinase activity in rat thecal-interstitial cells and mouse TM3 Leydig cells is positively associated with cAMP-specific phosphodiesterase activity.

Phosphodiesterases (PDEs) play a critical role in the regulation of intracellular cyclic nucleotide concentration and, consequently, regulate the state of cellular differentiation. We have reported that the Src-selective tyrosine kinase inhibitor, herbimycin A, potentiates luteinizing hormone (LH)-stimulated cAMP accumulation in culture media by ovarian thecal-interstitial cells (TIC; see Taylor, C and Terranova, P.F. (1995) Lipopolysaccharide inhibits rat ovarian thecal-interstitial cell steroid secretion in vitro. Endocrinology 136, 5527-5532). The present study was conducted to investigate the effects of herbimycin, and changes in Src tyrosine kinase activity, on PDE activity in rat TIC an in the mouse TM3 Leydig cell line. Treatment of TIC with herbimycin (1 microM) for 24 h inhibited basal and LH-stimulated PDE activity (approximately 50 and 70%, respectively) and was associated with an increase in cAMP and progesterone accumulation in culture media. Treatment of TM3 cells with herbimycin inhibited PDE activity and increased cAMP accumulation in a dose- and time-dependent manner. TM3 cell cultures challenged with herbimycin had lower Src tyrosine kinase activity than controls (approximately 50%); however, protein kinase A activity was unaffected. TM3 cells stably transfected with a dominant negative Src tyrosine kinase (TM3Srck-) had lower PDE activity than cells transfected with a G418 resistance gene alone (TM3pSV2neo) which served as control cells. Conversely, TM3 cells expressing a temperature-sensitive Src kinase had significantly greater PDE activity at the Src active temperature (35 degrees C; the temperature at which the enzyme is active) than TM3pSV2neo control cells grown at the same temperature. TM3 cell lysates hydrolyzed minimal amounts of cGMP, indicating a cAMP-specific PDE. Phosphodiesterase activity in both TM3 and rat TIC was sensitive to the PDE4-selective inhibitor RO20-1724, indicating the predominant active enzyme is probably a member of the cAMP-specific PDE4 family. From the present data, we conclude that a tyrosine kinase of the Src family may play an important role in regulating phosphodiesterase activity in thecal and Leydig cells, and thus regulate intracellular cAMP and the state of cellular differentiation.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1997

Metachronous development of malignant Leydig cell tumor.

Leydig cell tumor (LCT), a rare testicular tumor, is malignant in only about 10% of the cases. We report the case of a patient with bilateral malignant LCTs that developed metachronously. After undergoing a right inguinal orchiectomy for a malignant LCT at the age of 43 years, the patient was given cisplatin-based chemotherapy for suspected para-aortic lymph node metastasis. Eighteen months after the right orchiectomy, examination of a left testicular biopsy specimen showed a malignant LCT and a left inguinal orchiectomy was performed. Histologically, the initial malignant LCT exhibited a highly pleomorphic appearance with mitotic figures (58/10 HPF), whereas the second malignant LCT showed fewer mitoses (2/10 HPF). The proliferating cell nuclear antigen (PCNA)-labelling index in these tumors also differed (right-sided tumor, 50%; left-sided tumor, 28%). These findings suggest that the malignant LCT in the left testis developed as a second primary rather than as a metastatic tumor. There have been no known similar cases, although three cases of malignant LCT with contralateral metastasis have been reported.

Adult↗
PubMed1989

Growth hormone and insulin-like growth factor I stimulate Leydig cell steroidogenesis.

Leydig cells from 40 days old rats were incubated with or without human growth hormone (hGH) or insulin-like growth factor I (IGF-I) in the presence or absence of human chorionic gonadotropin (hCG), and testosterone and cyclic AMP (cAMP) levels in the medium were measured. Neither hGH nor IGF-I increased testosterone production in the absence of hCG in concentrations up to 1000 and 100 ng/ml, respectively. However, both peptides increased hCG-induced testosterone production in a dose-dependent manner. The maximal stimulatory concentrations of hGH and IGF-I were 100 and 50 ng/ml, respectively. Human GH did not further enhance the IGF-I-stimulated steroidogenesis. The hGH-augmented steroidogenesis was inhibited by anti-hGH IgG and anti-IGF-I IgG. hGH also enhanced hCG-stimulated cAMP production time dependently, suggesting that the stimulatory effect of hGH on steroidogenesis was due to an increased cAMP production. These data suggest that the effect of hGH might be mediated by locally produced IGF-I, which may act as a modulator on gonadal development in the presence of gonadotropin.

Animals↗
PubMed2003

Lansoprazole increases testosterone metabolism and clearance in male Sprague-Dawley rats: implications for Leydig cell carcinogenesis.

Leydig cell tumours (LCTs) are frequently observed during rodent carcinogenicity studies, however, the significance of this effect to humans remains a matter of debate. Many chemicals that produce LCTs also induce hepatic cytochromes P450 (CYPs), but it is unknown whether these two phenomena are causally related. Our aim was to investigate the existence of a liver-testis axis wherein microsomal enzyme inducers enhance testosterone metabolic clearance, resulting in a drop in circulating hormone levels and a consequent hypertrophic response from the hypothalamic-pituitary-testis axis. Lansoprazole was selected as the model compound as it induces hepatic CYPs and produces LCTs in rats. Male Sprague-Dawley rats were dosed with lansoprazole (150 mg/kg/day) or vehicle for 14 days. Lansoprazole treatment produced effects on the liver consistent with an enhanced metabolic capacity, including significant increases in relative liver weights, total microsomal CYP content, individual CYP protein levels, and enhanced CYP-dependent testosterone metabolism in vitro. Following intravenous administration of [14C]testosterone, lansoprazole-treated rats exhibited a significantly smaller area under the curve and significantly higher plasma clearance. Significant reductions in plasma and testicular testosterone levels were observed, confirming the ability of this compound to perturb androgen homeostasis. No significant changes in plasma LH, FSH, or prolactin levels were detected under our experimental conditions. Lansoprazole treatment exerted no marked effects on testicular testosterone metabolism. In summary, lansoprazole treatment induced hepatic CYP-dependent testosterone metabolism in vitro and enhanced plasma clearance of radiolabelled testosterone in vivo. These effects may contribute to depletion of circulating testosterone levels and hence play a role in the mode of LCT induction in lansoprazole-treated rats.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2000

A novel messenger ribonucleic acid homologous to human MAGE-D is strongly expressed in rat Sertoli cells and weakly in Leydig cells and is regulated by follitropin, lutropin, and prolactin.

We have cloned a novel complementary DNA whose expression was decreased in rat Sertoli cell cultures after treatment with FSH. This complementary DNA encodes a protein of 570 amino acids and shares 92% homology with the human MAGE-D protein. In contrast to other MAGE genes (A, B, or C), we have shown that MAGE-D expression was ubiquitous in healthy rat tissues. In the seminiferous tubules, the MAGE-D was expressed in Sertoli cells but not in germ cells as demonstrated by RT-PCR and in situ hybridization, whereas for the other MAGE genes, expression has been shown to be restricted to germ cells. Interestingly, MAGE-D was also detected for the first time in the female gonad by Northern blotting. In MLTC-1 cells (mouse Leydig tumor cell line-1), LH and PRL stimulated MAGE-D expression. Using hypophysectomized rats, it was confirmed that FSH decreased MAGE-D expression, whereas LH and PRL increased MAGE-D messenger RNA level in the whole testis most probably through a direct action on Leydig cells. As MAGE-D is present in both the seminiferous compartment and interstitium and hormonally regulated in each, it is possible that it has specific functions in each compartment during the development and the maintenance of the testis.

Amino Acid Sequence↗
PubMed2002

25-hydroxycholesterol is produced by testicular macrophages during the early postnatal period and influences differentiation of Leydig cells in vitro.

Leydig cells develop inappropriately in animals lacking testicular macrophages. We have recently found that macrophages from adult animals produce 25-hydroxycholesterol, an oxysterol involved in the differentiation of hepatocytes and keratinocytes. Therefore, we hypothesized that testicular macrophages also produce 25-hydroxycholesterol during the early postnatal period and that this oxysterol plays a role in the differentiation of Leydig cells. We assessed the production of 25-hydroxycholesterol and 25-hydroxylase mRNA by cultured testicular macrophages from rats at 10, 20, and 40 days of age. We also tested the long-term effects of 25-hydroxycholesterol on basal and LH-stimulated testosterone production, and 3beta-hydroxysteroid dehydrogenase activity as end points of Leydig cell differentiation in vitro. We found that testicular macrophages from animals at all ages produced both 25-hydroxycholesterol and 25-hydroxylase mRNA, with macrophages from 10-day-old animals having the highest steady-state levels of message. We also found that chronic exposure of Leydig cells to 25-hydroxycholesterol increased basal production of testosterone but decreased LH-stimulated steroidogenesis at all ages. Finally, 25-hydroxycholesterol increased 3beta-hydroxysteroid dehydrogenase activity in both progenitor and immature Leydig cells. These findings support the hypothesis that testicular macrophages play an important role in the differentiation of Leydig cells through the secretion of 25-hydroxycholesterol.

3-Hydroxysteroid Dehydrogenases↗
PubMed1987

Spent media from immature seminiferous tubules and Sertoli cells inhibit adult rat Leydig cell aromatase activity.

Adult rat Leydig cell aromatase activity is stimulated 2.5 fold by LH or dbcAMP. Spent media prepared from seminiferous tubules or Sertoli cells of immature rats depress both the basal and the LH stimulated estradiol syntheses (25 and 20% decreases, respectively). These inhibitory effects are further enhanced when FSH is added to the culture medium of seminiferous tubules or Sertoli cells. Rat serum as well as culture media from other cell lines are ineffective while seminiferous tubule media from other immature animals (mouse, guinea-pig, calf) inhibit the aromatase activity. This Sertoli cell factor is a heat stable protein (molecular weight greater than 10 kDa), different from the LHRH-like Sertoli cell compound, which acts on the aromatase activity at a step beyond the adenylate cyclase.

Animals↗
PubMed1985

Cultured Sertoli cell-mediated FSH stimulatory effect on Leydig cell steroidogenesis.

To determine the precise role of Sertoli cells in the stimulating effects of follicle stimulating hormone (FSH) on Leydig cell activity, porcine purified Leydig and Sertoli cells were cultured separately or together in a chemically defined medium in the absence or presence of porcine, FSH 50 ng/ml. Leydig cell activity was evaluated using two parameters: human chorionic gonadotropin (hCG) binding sites; and hCG-stimulated cAMP production and testosterone secretion. First, it was found that FSH increases Leydig cell activity in crude Leydig cell preparations (40-60% of Leydig cells), whereas it exerts no effect on purified Leydig cells (greater than 90% of Leydig cells). Second, FSH stimulates the activity of Leydig cells cocultured with Sertoli cells, whereas it remains without effect on purified Leydig cells cultured alone. This stimulating effect of FSH on Leydig cell activity is dependent on the Sertoli cell number in the coculture. These data 1) show that the stimulating effect of FSH on Leydig cell function is mediated by Sertoli cells and 2) support the concept of local control of Leydig cell function originating from Sertoli cells.

Animals↗
PubMed1990

Influence of coculture with Sertoli cells on steroidogenesis in immature rat Leydig cells.

The hypothesis has been advanced that Sertoli cells produce one or more follicle-stimulating hormone (FSH)-dependent paracrine factors which stimulate Leydig cell maturation and steroidogenesis. In an attempt to identify these factors we studied the effect of coculture with Sertoli cells on the steroidogenic capacity of immature Leydig cells. It is demonstrated that coculture, during a period of 6 days, markedly increases the capacity of the Leydig cells to secrete C21-steroids (progesterone, 17 alpha-hydroxyprogesterone, 20 alpha-hydroxypregn-4-en-3-one) and C19-steroids (testosterone, androst-4-ene-3,17-dione) in response to stimulation with luteinizing hormone (LH). Pretreatment of the cocultures on days 4, 5 and 6 with low concentrations of gonadotropins further enhances the steroidogenic response to LH. This pretreatment results in an overall increase in steroid output. At low concentrations of Sertoli cells and when short incubation times are used, pretreatment with FSH is clearly more effective than pretreatment with LH. Pretreatment with gonadotropins also results in a disproportionate increase in C19 output caused by increased conversion of C21 precursors into C19-steroids. This effect is also observed in Leydig cell monocultures and is mainly due to LH action on Leydig cells. Finally pretreated cocultures display a selective increase in testosterone output. The latter effect is caused by FSH-dependent conversion of androstenedione into testosterone in Sertoli cells. Pretreated cocultures can be maintained for at least 28 days. During this entire period their basal steroid output increases. Using a two-chamber culture system it is demonstrated that direct cell-cell interactions are not required to observe the stimulatory effects of coculture. One or more diffusible factors are involved and continuous contact with these factors is required to maintain the effect. Immunoneutralization experiments using an insulin-like growth factor (IGF-I) antiserum show that IGF-I is an important permissive factor to maintain steroidogenesis in isolated Leydig cells and in cocultures. Under none of the conditions studied, however, does the antiserum neutralize the stimulatory effect of coculture. It is concluded that the stimulatory effects of coculture on the testosterone output of Leydig cells are complex and that important diffusible mediators still remain to be identified.

Animals↗
PubMed2004

Progenitor cells of the testosterone-producing Leydig cells revealed.

The cells responsible for production of the male sex hormone testosterone, the Leydig cells of the testis, are post-mitotic cells with neuroendocrine characteristics. Their origin during ontogeny and regeneration processes is still a matter of debate. Here, we show that cells of testicular blood vessels, namely vascular smooth muscle cells and pericytes, are the progenitors of Leydig cells. Resembling stem cells of the nervous system, the Leydig cell progenitors are characterized by the expression of nestin. Using an in vivo model to induce and monitor the synchronized generation of a completely new Leydig cell population in adult rats, we demonstrate specific proliferation of vascular progenitors and their subsequent transdifferentiation into steroidogenic Leydig cells which, in addition, rapidly acquire neuronal and glial properties. These findings, shown to be representative also for ontogenetic Leydig cell formation and for the human testis, provide further evidence that cellular components of blood vessels can act as progenitor cells for organogenesis and repair.

Animals↗
PubMed1989

Modulatory effects of adrenergic agonists on testosterone secretion from rat dispersed testicular cells or Percoll-purified Leydig cells.

1. Freshly dispersed testicular interstitial cells as well as Percoll-purified Leydig cells were studied in vitro in order to evaluate the effect of adrenergic agonists on testosterone (T) secretion. 2. Epinephrine and phenylephrine did not change the rate of T release under basal conditions in freshly dispersed interstitial cells, but enhanced it during human chorionic gonadotropin (hCG) stimulation. Norepinephrine and clonidine had no effect on T secretion. 3. In contrast, in Percoll-purified Leydig cells epinephrine increased T release both under basal and hCG-stimulated conditions. 4. These data demonstrate that neurotransmitters may participate in T secretion from isolated Leydig cells.

Animals↗
PubMed2006

Enucleation for prepubertal leydig cell tumor.

PURPOSE: Leydig cell tumors in children are rare, comprising only 4% to 9% of all primary testis tumors in prepubertal males. Almost all of these boys present with isosexual precocious pseudopuberty associated with increased testosterone, low gonadotropin levels and a testis mass. We present our experience with testis sparing enucleation of Leydig cell tumor in prepubertal boys. MATERIALS AND METHODS: Two patients presented with isosexual precocious puberty at ages 6 and 9 years. Each patient had a well circumscribed, painless testicular mass, increased serum testosterone (101 and 444 ng/dl [normal 0 to 25]), normal gonadotropins and negative alpha-fetoprotein levels. Both patients underwent successful enucleation of the testis mass following proper testis oncological surgical principles. RESULTS: Both patients had normalization of the serum testosterone following enucleation of the Leydig cell tumor. At 9 and 44 months of followup they have maintained normal ipsilateral testicular volume compared to the contralateral gonad, and 1 patient entered puberty spontaneously at 1 year postoperatively. Neither patient suffered any morbidity, and both have presumably benefited from preservation of the involved gonad with preserved testicular volume. CONCLUSIONS: Prepubertal boys with isosexual precocious pseudopuberty, an isolated testis mass, increased testosterone and low or normal gonadotropin levels can reliably be diagnosed with Leydig cell tumors. Based on the ability to establish the diagnosis preoperatively and the universal benign behavior of unilateral, prepubertal Leydig cell tumor, we believe these patients are best treated with testis sparing enucleation of the tumor. In view of the high likelihood that this tumor in prepubertal boys is benign, a transscrotal surgical approach should be considered.

Child↗
PubMed1987

Modulation of Leydig cell functions by culture with Sertoli cells or with Sertoli cell-conditioned medium: effect of insulin, somatomedin-C and FSH.

The potential regulatory action of Sertoli cells on Leydig cell functions has been investigated by using a coculture system of Leydig and Sertoli cells obtained from immature pig or by culturing Leydig cells with Sertoli cell-conditioned medium (SCCM). Coculture of Leydig and Sertoli cells for 48 h in the absence of insulin or somatomedin-C (Sm-C), produced a small but significant increase in both hCG receptors and hCG-induced testosterone production. Addition to the medium of pFSH (100 ng/ml), insulin (5 micrograms/ml) or somatomedin-C (50 ng/ml) produced a marked increase in these two parameters of Leydig cell function. A further significant increase was observed when pFSH was associated with insulin or Sm-C. In contrast, coculture of Leydig cells with aortic endothelial cells decreased both the hCG receptor number and the hCG responsiveness. SCCM stimulated Leydig cell testosterone production following a 4 h incubation. The stimulation depended upon the amount of SCCM used and the conditions in which Sertoli cells were cultured. The most active was the medium from cells cultured in the presence of pFSH and insulin at high concentrations. Since pig Sertoli cells have specific somatomedin-C receptors, but not insulin receptors, it is likely that the effect of micromolar concentrations of insulin are exerted through Sm-C receptors. In addition, SCCM produced a long-term effect after 48 h incubation. SCCM from cells cultured in the absence of insulin and pFSH inhibited both the hCG receptor number and hCG responsiveness. A similar inhibition was observed with SCCM medium from cells cultured without insulin but with pFSH.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗