Effects of hypophysectomy and human chorionic gonadotrophin on Leydig cell function in mature rats

1990 ◽  
Vol 126 (3) ◽  
pp. 367-NP ◽  
Author(s):  
D. M. Stocco ◽  
K. J. Teerds ◽  
M. van Noort ◽  
F. F. G. Rommerts
Keyword(s):  
Leydig Cell ◽  
Leydig Cells ◽  
Cell Function ◽  
Fold Increase ◽  
Specific Protein ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Cell Functions ◽  
Complete Restoration ◽  
Hypophysectomized Rats

ABSTRACT The biochemical activities involved in the maintenance of Leydig cell functions, and the effects of hypophysectomy and human chorionic gonadotrophin (hCG) on these functions are largely unknown. In the present study, adult hypophysectomized rats were used as a model to determine the effects of these treatments on a number of biochemical and morphological parameters. After 33 days of hypophysectomy, the morphology of the Leydig cells had been drastically altered. In addition, α-naphthol and β-naphthol esterase activity as well as the steroidogenic capacity of the Leydig cells were greatly reduced at this time. In contrast, the level of sterol carrier protein 2 (SCP2), a Leydig cell-specific protein, was affected by hypophysectomy much less than the other parameters measured. Two daily injections of hCG to rats hypophysectomized for 31 days resulted in no change in the morphology of the Leydig cells, or in their proliferative activity. Non-specific esterase activities were also unaffected by 2 days of treatment with hCG. However, two injections of hCG to rats hypophysectomized for 31 days resulted in nearly complete restoration of steroidogenic capacity, and a 3·5-fold increase in the level of SCP2. These findings indicate that hypophysectomy results in significant morphological and biochemical changes in Leydig cells, and that hCG is capable of restoring some of these capacities within a short time. Journal of Endocrinology (1990) 126, 367–375

Studies on the testicular source of inhibin and its route of secretion in rams: failure of the Leydig cell to secrete inhibin in response to a human chorionic gonadotrophin/LH stimulus

1991 ◽  
Vol 130 (1) ◽  
pp. 107-114 ◽  
Author(s):  
A. J. Tilbrook ◽  
D. M. de Kretser ◽  
I. J. Clarke
Keyword(s):  
Leydig Cell ◽  
Leydig Cells ◽  
Jugular Vein ◽  
Plasma Concentrations ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Spermatic Vein ◽  
Jugular Veins ◽  
Testicular Vein ◽  
Peripheral Plasma

ABSTRACT To determine whether Leydig cells produce inhibin in the ram, Leydig cells were stimulated by administering human chorionic gonadotrophin (hCG) or raising the levels of endogenous LH by an injection of gonadotrophin releasing hormone (GnRH). Plasma concentrations of testosterone increased in the 72 h after either a single injection (P < 0·05) or two injections (P < 0·01) of hCG. Plasma concentrations of inhibin were not significantly influenced by either one or two injections of hCG. Administration of GnRH (1 μg) caused an 11-fold increase in plasma concentrations of LH but did not influence concentrations of inhibin in either the jugular or testicular veins (pampiniform plexus). In contrast, concentrations of testosterone were increased by about fourfold in both jugular (P < 0·01) and testicular (P < 0·05) veins. The concentrations of inhibin in the testicular vein were 1·3-fold higher than in the peripheral plasma (P < 0·05) both before and following treatment with GnRH whereas the concentrations of testosterone were 18- to 21-fold greater than in peripheral concentrations. In view of the difference in concentrations of inhibin between testicular and jugular veins, in a further experiment a sample was taken from the jugular vein, a vein located in the tunica vasculosa of the testis (testicular vein) and from a vein (spermatic vein) and lymph vessels located in the spermatic cord. The mean (± s.e.m.) concentrations of inhibin were highest in the testicular lymph (45·93±4·21 μg/l; P < 0·001) compared with the peripheral (4·14±0·31 μg/l), spermatic (8·0±1·17 μg/l) or testicular (6·4±0·82 μg/l) plasma. Plasma concentrations of inhibin were significantly higher in the spermatic vein than in the testicular vein (P < 0·05) and jugular vein (P < 0·01), and concentrations of inhibin in the testicular vein were significantly (P < 0·05) higher than in the jugular vein. There were no significant differences in the concentrations of testosterone in the spermatic vein, testicular vein or testicular lymph but the concentrations of testosterone in the peripheral plasma were significantly (P < 0·05) less than in the testicular plasma or lymph. These results suggest that, in the ram, the Leydig cell does not respond to hCG or endogenous LH by secreting inhibin or by influencing other cells within the testis to secrete inhibin within the time-frame of these experiments. The low testicular to jugular differences in the concentration of inhibin and the high concentrations of inhibin in the testicular lymph suggest that the lymph may be an important route of secretion of inhibin from the testis in the ram. Journal of Endocrinology (1991) 130, 107–114

Effects of recombinant human FSH in immature hypophysectomized male rats: evidence for Leydig cell-mediated action on spermatogenesis

1994 ◽  
Vol 141 (3) ◽  
pp. 449-457 ◽  
Author(s):  
T Matikainen ◽  
J Toppari ◽  
K K Vihko ◽  
I Huhtaniemi
Keyword(s):  
Leydig Cell ◽  
Leydig Cells ◽  
Cell Function ◽  
Serum Testosterone ◽  
Male Rats ◽  
Seminiferous Tubules ◽  
Spermatogenic Cells ◽  
Hypophysectomized Rats ◽  
First Time ◽  
Recombinant Human Fsh

Abstract The mode of FSH actions within the testis was studied in immature hypophysectomized male rats by treatment with recombinant human FSH (recFSH, Org 32489). To elucidate the involvement of Leydig cells and androgens in the maintenance of spermatogenesis in FSH-treated hypophysectomized rats further, the recFSH treatment was given both alone and after destruction of Leydig cells with ethane-1,2-dimethane sulphonate (EDS). Three days after hypophysectomy (at 31 days of age) the rats were given one i.p. injection of vehicle or EDS and, 4 days later, they were implanted with osmotic minipumps releasing either 0·9% (w/v) NaCl or 1 IU recFSH/day. Recombinant FSH alone increased testicular weights 2·5-fold in 7 days (P<0·01). The effect of FSH was similar in EDS-pretreated rats (P<0·01). Testicular testosterone increased from 6·5 ± 1·6 to 16·9 ± 5·3 (s.e.m.) pmol/g tissue (P<0·05) and serum testosterone from 0·12 ± 0·02 to 0·22 ± 0·03 nmol/l (P<0·05) when the rats were treated with recFSH. EDS alone did not affect testicular testosterone but, when combined with recFSH, it totally abolished the stimulatory effect of FSH on testosterone. Testicular binding of 125I-labelled iodo human chorionic gonadotrophin (hCG) and 125I-labelled iodo recFSH was increased 2·5- and 2·1-fold respectively with recFSH treatment (P<0·01). EDS, either alone or with FSH, abolished specific testicular hCG binding (P<0·01), but had no effect on that of recFSH. However, FSH increased its own receptors only in animals not treated with EDS. Histological analysis of the testes revealed that the diameters of the seminiferous tubules increased from 115 ± 6·1 to 160 ± 7·2 μm (P<0·05) with recFSH, and a comparable increase was observed when EDS treatment preceded that of recFSH (143 ± 1·5 μm, P<0·05 vs. controls). Quantification of the spermatogenic cells indicated that recFSH supported the progression of spermatogenesis, as shown by increased number of meiotic and haploid spermatogenic cells (P<0·05). In all EDS-treated animals, spermatogenesis was severely disturbed and only a few spermatids were seen. In conclusion: (1) these results further support the suggestion that FSH has indirect stimulatory effects on Leydig cell function, (2) the completion of meiosis and spermiogenesis are supported by FSH, the effect of which is enhanced by the presence of Leydig cells, suggesting its dependence on androgens, and (3) we show for the first time that FSH is able to stimulate its own receptors only in the presence of Leydig cell-derived factors, probably androgens. Journal of Endocrinology (1994) 141, 449–457

Proliferation and differentiation of possible Leydig cell precursors after destruction of the existing Leydig cells with ethane dimethyl sulphonate: the role of LH/human chorionic gonadotrophin

1989 ◽  
Vol 122 (3) ◽  
pp. 689-NP ◽  
Author(s):  
K. J. Teerds ◽  
D. G. de Rooij ◽  
F. F. G. Rommerts ◽  
R. van den Hurk ◽  
C. J. G. Wensing
Keyword(s):  
Leydig Cell ◽  
Proliferative Activity ◽  
Leydig Cells ◽  
Precursor Cells ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Adult Rats ◽  
Proliferation And Differentiation ◽  
Endocrine Factors

ABSTRACT The influence of LH levels on the proliferation and differentiation of possible Leydig cell precursors was investigated in adult rats, after the destruction of the existing Leydig cells with the cytotoxic drug ethane dimethyl sulphonate (EDS). In rats bearing a testosterone implant which prevented the rise in plasma LH levels and kept them within the normal range after the destruction of the Leydig cells, the proliferative activity of possible Leydig cell precursors still increased seven- to eightfold 2 days after EDS administration. Apparently, in this situation, locally produced factors, and not LH, may play a role in the stimulation of proliferation. The proliferative activity of the possible precursor cells could be further stimulated by treating rats with daily injections of human chorionic gonadotrophin (hCG) following EDS administration. It was concluded that the proliferative activity of possible Leydig cell precursors is probably regulated by both paracrine and endocrine factors. Almost no Leydig cells were formed in the rats bearing a testosterone implant during the first 4 weeks after EDS administration. When these rats were treated with hCG, starting 28 days after administration of EDS, a substantial number of Leydig cells was found after 2 days, and these cells also showed 3β-hydroxysteroid dehydrogenase (3β-HSD) and α-naphtyl esterase (α-NE) activity. When hCG treatment was started at 14 or 21 days after EDS administration, some cells with the nuclear characteristics of Leydig cells were present after 2 days, but no 3β-HSD or α-NE activity could be detected. Finally, when hCG treatment was started directly after EDS administration, a considerable number of Leydig cells was found 14 days after EDS, and some of these cells already showed 3β-HSD and α-NE activity. It is concluded that precursor cells are able to develop into advanced precursor cells at normal LH levels, and that the rate of development of new Leydig cells strongly depends upon LH/hCG levels. Journal of Endocrinology (1989) 122, 689–696

Effects of FSH on Leydig cell morphology and function in the hypogonadal mouse

1992 ◽  
Vol 135 (3) ◽  
pp. 517-NP ◽  
Author(s):  
P. J. O'Shaughnessy ◽  
M. K. Bennett ◽  
I. S. Scott ◽  
H. M. Charlton
Keyword(s):  
Leydig Cell ◽  
Sertoli Cells ◽  
Leydig Cells ◽  
Cell Function ◽  
Reductase Activity ◽  
Fold Increase ◽  
Paracrine Factors ◽  
Androgen Synthesis ◽  
Congenital Deficiency ◽  
Stimulation Of

ABSTRACT The hypogonadal (hpg) mouse has a congenital deficiency in gonadotrophin-releasing hormone and the gonads consequently lack exposure to endogenous gonadotrophins during development. To determine the effect of FSH on Leydig cell function in these animals adult hpg mice were injected twice daily with FSH (2 μg injections) or LH (40 ng injections, the presumed LH contamination of FSH used). Following FSH treatment there was a clear stimulation of the seminiferous epithelium and in animals injected with FSH plus [3H]thymidine, the incorporation of label was largely confined to the germ cells with no apparent uptake by the Sertoli cells. In FSH-treated testes the Leydig cells contained numerous large lipid droplets, similar to the unstimulated hpg testis. There was no evidence of the interstitial hyperplasia which is observed following injection of high doses of LH (2 pg twice daily). There was no change in basal androgen content of the testis in vivo following FSH treatment but injection of a maximal dose of human chorionic gonadotrophin (hCG), 1 h before death, markedly increased testicular androgen content only in the FSH-treated group. Testicular androgen production in vitro was significantly increased following FSH treatment both under basal conditions (FSH-treated, 17·4 pmol/testis; control, 1·46 pmol/testis) and during stimulation by hCG (FSH-treated, 940 pmol/testis; control, 81 pmol/testis). Associated with the increased androgen production following FSH treatment there were significant increases in the activities of three steroidogenic enzymes; cholesterol side-chain cleavage (186-fold increase over control), 17α-hydroxylase (103-fold increase) and 17-ketosteroid reductase (177-fold increase). The fourth enzyme involved in androgen synthesis, 3β-hydroxysteroid dehydrogenase, shows relatively high activity in the control hpg testis and was only increased by sixfold following FSH treatment. There was no effect of FSH on 5α-reductase activity. Results show that FSH causes a marked stimulation of the steroidogenic capacity of the hpg testis. Leydig cells do not contain FSH receptors and it is assumed that FSH acts through paracrine factors released by the Sertoli cells. Journal of Endocrinology (1992) 135, 517–525

BINDING OF HUMAN CHORIONIC GONADOTROPHIN BY RAT TESTIS: EFFECT OF SEXUAL MATURATION, CRYPTORCHIDISM AND HYPOPHYSECTOMY

1975 ◽  
Vol 64 (1) ◽  
pp. 59-66 ◽  
Author(s):  
JOACHIM FROWEIN ◽  
WOLFGANG ENGEL
Keyword(s):  
Dissociation Constant ◽  
Sexual Maturation ◽  
Leydig Cells ◽  
Binding Capacity ◽  
Specific Binding ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Scatchard Analysis ◽  
Rat Testis ◽  
Relative Binding

SUMMARY The specific binding of 125I-labelled human chorionic gonadotrophin (HCG) by rat testicular homogenate as compared with isolated Leydig cells differs with respect to total binding capacity but not to the dissociation constant (KD) as revealed by Scatchard analysis. The maximal binding capacity for [125I]HCG of crude testicular homogenate was 95 ng/g rat testis. Hypophysectomy causes a decline in binding capacity within the first three days but on the 20th and 30th day after hypophysectomy the relative binding capacity no longer differs from that of controls. Binding capacity is enhanced in cryptorchid testes relative to normal, and increases during sexual maturation to a peak shortly before puberty.

scholarly journals LH/chorionic gonadotropin signaling pathway involves protein tyrosine phosphatase activity downstream of protein kinase A activation: evidence of an obligatory step in steroid production by Leydig cells

2001 ◽  
Vol 170 (2) ◽  
pp. 403-411 ◽  
Author(s):  
FC Maciel ◽  
C Poderoso ◽  
A Gorostizaga ◽  
C Paz ◽  
EJ Podesta
Keyword(s):  
Protein Kinase ◽  
Chorionic Gonadotropin ◽  
Leydig Cell ◽  
Protein Tyrosine Phosphatase ◽  
Leydig Cells ◽  
Tyrosine Phosphatase ◽  
Zona Fasciculata ◽  
Stimulatory Action ◽  
Protein Tyrosine ◽  
Cell Functions

Our recent reports indicate that protein tyrosine phosphorylation is an obligatory component of the mechanism of action of ACTH in its stimulatory action of corticosteroid production in adrenal zona fasciculata (ZF). The role of protein tyrosine phosphatase (PTP) activity in the regulation of steroidogenesis by LH/chorionic gonadotropin (CG) was tested using cell-permeable PTP inhibitors. Thus, PTP inhibition blocks LH- and 8-bromo-cAMP-stimulated testosterone production by Leydig cells without affecting 22(R)OH-cholesterol-supported steroidogenesis, similar results to those obtained in the adrenal ZF/ACTH system, leading us to propose that PTP action is an obligatory and common step in the cascade triggered by both hormones. Then, we continued the study testing whether LH modulates PTP activity in MA-10 cells, a Leydig cell line. In this regard, we observed by an in-gel PTP assay two PTPs of 110 and 50 kDa that are activated by hormone and 8-bromo-cAMP activation of the cells. Moreover, there is a transient increase by the second messenger in total PTP activity that correlates with the higher activity displayed by the 110 and 50 kDa proteins in the in-gel assay. In accordance with these results, analysis of tyrosine phosphorylated proteins showed the LH-induced dephosphorylation of proteins of 120, 68 and 50 kDa. The results of this study indicate that PTPs play an important role in the regulation of Leydig cell functions and that there exists a cross talk between serine/threonine phosphorylation and tyrosine dephosphorylation mediated by hormone-activated cAMP-dependent protein kinase and PTPs. These results are the first evidence of PTP having a role in LH/CG-stimulated steroidogenesis.

scholarly journals Testosterone Response of Cryptorchid and Hypophysectomized Rats to Human Chorionic Gonadotrophin (hCG) Stimulation

1985 ◽  
Vol 38 (4) ◽  
pp. 445 ◽  
Author(s):  
Y M Hodgson ◽  
DM de Kretser
Keyword(s):  
Single Injection ◽  
Serum Testosterone ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Testosterone Levels ◽  
Hypophysectomized Rats ◽  
Secondary Rise

The testosterone responses to a single injection of HCG (100 i.u.) in hypophysectomized (hypox.), cryptorchid or sham-operated rats were followed over a 5-day period. In sham-operated rats, hCG induced a biphasic rise in serum testosterone, peaks being observed at 2 and 72 h. Reduced testis weights, elevated FSH and LH levels and reduced serum testosterone levels were found after 4 weeks of cryptorchidism, but hCG stimulation resulted in a normal 2 h peak in serum testosterone. However, the secondary rise at 72 h in cryptorchid rats was significantly lower than sham-operated rats.

Effect of lanosterol on the in vitro maturation in semi-defined culture system of prepubertal ewe oocytes

Zygote ◽  
2011 ◽  
Vol 22 (1) ◽  
pp. 50-57 ◽  
Author(s):  
F. Marco-Jiménez ◽  
J.S. Vicente ◽  
M.P. Viudes-de-Castro
Keyword(s):  
Oxygen Concentration ◽  
Cell Function ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Low Oxygen ◽  
Oocyte Growth ◽  
Important Indicator ◽  
Nuclear Maturation ◽  
Defined Culture

SummaryThe choice of medium and supplements can affect meiotic regulation and may have an impact on the regulation of mammalian oocyte growth and embryonic cell function. The aim of the present study was to assess the effects of oxygen concentration and endogenous lanosterol on the in vitro maturation (IVM) media without serum and based on recombinant human chorionic gonadotrophin in prepubertal ewe oocytes. Firstly, the effect of varying oxygen concentrations (5% and 20%) during IVM in TCM-199 supplemented (4 mg/ml bovine serum albumin (BSA), 100 μM cysteamine, 0.3 mM sodium pyruvate, 0.1 UI/ml recombinant follicle-stimulating hormone (r-FSH; Gonal-F® 75 UI, Serono, Italy), 0.1 UI/ml recombinant leuteinizing hormone (r-LH; Lhadi® 75 UI, Serono, Italy) and 1 μg/ml estradiol-17β) on subsequent nuclear maturation of oocytes examined under ultraviolet light following staining with bisbenzimide (Hoechst 33342) was investigated. Secondly, two concentrations of lanosterol (0, 10 and 50 μM) were added to the IVM medium. Nuclear maturation of oocytes was examined as previously. Lipid content in oocytes, an important indicator of cytoplasmic maturity, was also measured using Nile red fluorescent stain. The results showed that low oxygen concentration affected the nuclear maturation. Similarly, a significantly higher rate of meiosis resumption was observed with 10 μM (72.3%) of lanosterol compared with the control (51.8%) or 50 μM of lanosterol (59.4%). A significantly higher content of lipids was also observed with 10 and 50 μM of lanosterol (7.3 ± 0.2 × 106 and 7.4 ± 0.2 × 106 arbitrary units of fluorescence) compared with the control (6.7 ± 0.2 × 106 arbitrary units of fluorescence). The results indicate that 10 μM lanosterol during IVM in medium without serum and based on recombinant human chorionic gonadotrophin has a positive effect on maturation of prepubertal ewe oocytes.

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