Reversal of long-term LH deprivation on testosterone secretion and Leydig cell volume, number and proliferation in adult rats

1990 ◽  
Vol 127 (1) ◽  
pp. 47-NP ◽  
Author(s):  
D. S. Keeney ◽  
R. L. Sprando ◽  
B. Robaire ◽  
B. R. Zirkin ◽  
L. L. Ewing

ABSTRACT The purpose of this study was to determine whether Leydig cell volume and function could recover fully from long-term LH deprivation upon restoration of endogenous LH secretion, and whether the restoration of LH would elicit a mitogenic response, i.e. stimulate Leydig cell proliferation or affect Leydig cell number per testis. LH secretion was inhibited by treating adult rats with testosterone and oestradiol-filled (TO) silicone elastomer implants (16 weeks), and was restored by removing the implants. Changes in serum concentrations of LH and FSH, LH-stimulated testosterone secretion by testes perfused in vitro, Leydig cell volume and number per testis, average Leydig cell volume and Leydig cell [3H]thymidine incorporation were measured at weekly intervals following implant removal. The TO implants inhibited (P < 0·01) LH secretion, but serum concentrations of FSH were not significantly different (P > 0·10) from control values. After implant removal, serum LH returned to control values within 1 week, whereas serum FSH increased twofold (P < 0·01) and returned to control values at 4 weeks. LH-stimulated in-vitro testosterone secretion was inhibited by more than 99% in TO-implanted rats, but increased (P < 0·01) to 80% of control values by 8 weeks after implant removal. The total volume of Leydig cells per testis and the volume of an average Leydig cell were 14 and 19% of control values respectively, after 16 weeks of TO implantation (P < 0·01), but returned to 83 and 86% of controls (P > 0·10) respectively, by 6 weeks after implant removal. Leydig cell proliferation ([3H]thymidine labelling index) was low (< 0·1%) in both control and TO-implanted rats, increased (P < 0·01) fivefold from 1 to 4 weeks after implant removal and then declined to control values at 6 weeks. The increase in Leydig cell [3H]thymidine incorporation was mimicked by treating TO-implanted rats with exogenous LH, but not FSH. Leydig cells were identified in both the interstitium and the lamina propria of the seminiferous epithelium. The proportion of Leydig cell nuclei in the lamina propria was 30-fold greater (P < 0·01) at 1 and 3 weeks after implant removal (3%) compared with that for control and TO-implanted rats (0·1%). Total Leydig cell number per testis was marginally but not significantly (P = 0·06) decreased in rats treated with TO implants for 16 weeks when compared with controls (18·4±2·2 vs 25·4±1·2 × 106). Three weeks after implant removal, the numbers of Leydig cells per testis were identical (26·8±2·8 × 106) to those in control animals. These results not only demonstrate dramatic morphogenic effects of LH on mature rat Leydig cells, but also suggest that endogenous LH might be mitogenic at least to a subpopulation of Leydig cells. Journal of Endocrinology (1990) 127,47–58

2020 ◽  
Vol 35 (12) ◽  
pp. 2663-2676
Author(s):  
Valentina Mularoni ◽  
Valentina Esposito ◽  
Sara Di Persio ◽  
Elena Vicini ◽  
Gustavo Spadetta ◽  
...  

Abstract STUDY QUESTION What are the consequences of ageing on human Leydig cell number and hormonal function? SUMMARY ANSWER Leydig cell number significantly decreases in parallel with INSL3 expression and Sertoli cell number in aged men, yet the in vitro Leydig cell androgenic potential does not appear to be compromised by advancing age. WHAT IS KNOWN ALREADY There is extensive evidence that ageing is accompanied by decline in serum testosterone levels, a general involution of testis morphology and reduced spermatogenic function. A few studies have previously addressed single features of the human aged testis phenotype one at a time, but mostly in tissue from patients with prostate cancer. STUDY DESIGN, SIZE, DURATION This comprehensive study examined testis morphology, Leydig cell and Sertoli cell number, steroidogenic enzyme expression, INSL3 expression and androgen secretion by testicular fragments in vitro. The majority of these endpoints were concomitantly evaluated in the same individuals that all displayed complete spermatogenesis. PARTICIPANTS/MATERIALS, SETTING, METHODS Testis biopsies were obtained from 15 heart beating organ donors (age range: 19–85 years) and 24 patients (age range: 19–45 years) with complete spermatogenesis. Leydig cells and Sertoli cells were counted following identification by immunohistochemical staining of specific cell markers. Gene expression analysis of INSL3 and steroidogenic enzymes was carried out by qRT-PCR. Secretion of 17-OH-progesterone, dehydroepiandrosterone, androstenedione and testosterone by in vitro cultured testis fragments was measured by LC-MS/MS. All endpoints were analysed in relation to age. MAIN RESULTS AND THE ROLE OF CHANCE Increasing age was negatively associated with Leydig cell number (R = −0.49; P &lt; 0.01) and concomitantly with the Sertoli cell population size (R= −0.55; P &lt; 0.001). A positive correlation (R = 0.57; P &lt; 0.001) between Sertoli cell and Leydig cell numbers was detected at all ages, indicating that somatic cell attrition is a relevant cellular manifestation of human testis status during ageing. INSL3 mRNA expression (R= −0.52; P &lt; 0.05) changed in parallel with Leydig cell number and age. Importantly, steroidogenic capacity of Leydig cells in cultured testis tissue fragments from young and old donors did not differ. Consistently, age did not influence the mRNA expression of steroidogenic enzymes. The described changes in Leydig cell phenotype with ageing are strengthened by the fact that the different age-related effects were mostly evaluated in tissue from the same men. LIMITATIONS, REASONS FOR CAUTION In vitro androgen production analysis could not be correlated with in vivo hormone values of the organ donors. In addition, the number of samples was relatively small and there was scarce information about the concomitant presence of potential confounding variables. WIDER IMPLICATIONS OF THE FINDINGS This study provides a novel insight into the effects of ageing on human Leydig cell status. The correlation between Leydig cell number and Sertoli cell number at any age implies a connection between these two cell types, which may be of particular relevance in understanding male reproductive disorders in the elderly. However aged Leydig cells do not lose their in vitro ability to produce androgens. Our data have implications in the understanding of the physiological role and regulation of intratesticular sex steroid levels during the complex process of ageing in humans. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by grants from Prin 2010 and 2017. The authors have no conflicts of interest. TRIAL REGISTRATION NUMBER N/A.


2003 ◽  
Vol 77 (5) ◽  
pp. 3297-3300 ◽  
Author(s):  
Ronan Le Goffic ◽  
Thomas Mouchel ◽  
Annick Ruffault ◽  
Jean-Jacques Patard ◽  
Bernard Jégou ◽  
...  

ABSTRACT Mumps virus is responsible for sterility. Here, we show that the mumps virus infects Leydig cells in vitro and totally inhibits testosterone secretion and that ribavirin in mumps virus-infected Leydig cell cultures completely restores testosterone production. Moreover, we show that gamma interferon-induced protein 10 (IP-10) is highly expressed by mumps virus-infected Leydig cells and that ribavirin does not block IP-10 production.


1984 ◽  
Vol 102 (3) ◽  
pp. 319-327 ◽  
Author(s):  
R. M. Sharpe ◽  
I. Cooper ◽  
D. G. Doogan

ABSTRACT Adult rats were made unilaterally cryptorchid (UCD) and 6–7 weeks later Leydig cells were isolated from the scrotal and abdominal testes and their capacity to secrete testosterone in vitro was compared. Basal testosterone production by Leydig cells from the abdominal testes of UCD rats was lowered, compared with cells from the contralateral scrotal testes, whilst their responsiveness to both human chorionic gonadotrophin and an LH releasing hormone agonist was enhanced two- to threefold (P< 0·001) compared both with cells from the contralateral scrotal testes and with cells isolated from untreated rats of the same age. In the UCD rats, concentrations of testosterone in testicular interstitial fluid (IF) were reduced (P< 0·001) by 70–90% in abdominal, compared with scrotal, testes. A similar reduction was evident in the levels of testosterone in spermatic venous blood, and both this decrease and that in IF levels of testosterone varied according to the degree of testicular involution. The ontogeny of the above changes was investigated. After induction of unilateral cryptorchidism, the weight of the abdominal compared with the scrotal testis declined slowly, such that by day 5 there was only a 25% reduction in weight compared with a 70% reduction by day 40. In contrast, the levels of testosterone in IF from abdominal testes declined rapidly, such that by day 5 an 80% reduction was attained, compared with scrotal testes, with little further change by day 40. Hormone-stimulated testosterone production by Leydig cells isolated from the abdominal testes was unchanged or marginally reduced over the first 3 days compared with cells from the scrotal testes, but by day 5 there was a significant increase in responsiveness; this increase was of smaller magnitude than that evident at day 40. These results suggest a possible association between the fall in intratesticular levels of testosterone induced by unilateral cryptorchidism and the Leydig cell hypertrophy and hyper-responsiveness that occurs in the same testes. The implications with respect to altered Sertoli–Leydig cell interaction are discussed. J. Endocr. (1984) 102, 319–327


Zygote ◽  
2004 ◽  
Vol 12 (4) ◽  
pp. 293-299 ◽  
Author(s):  
Michela d'Istria ◽  
Ismene Serino ◽  
Gaia Izzo ◽  
Diana Ferrara ◽  
Gianluca De Rienzo ◽  
...  

This study was conducted to verify the effect(s) of melatonin treatment on frog Leydig cells. Morphological observation after melatonin treatment indicates that many frog Leydig cells show degenerative changes (i.e. heterochromatic nuclei, loss of cellular adhesion) while in adjacent germinal tubules several Sertoli cells show heterochromatic nuclei, confirming the presence of a paracrine effect between interstitial and germinal compartments. The effect of melatonin on frog Leydig cell steroidogenesis was investigated in in vitro experiments; after 6 h of incubation melatonin severely inhibits both control and GnRH-induced testosterone secretion. In addition, in order to verify the effect of indolamine on frog Leydig cell activity, we investigated, by in situ hybridization, the presence of frog relaxin (fRLX, a transcript specifically expressed by these cells) in the testes of melatonin-injected animals after 48 h. fRLX signal completely disappeared from the testis of melatonin-injected frogs. The results of the present study indicate that melatonin treatment provokes Leydig cell morphological changes, blocks GnRH-antagonist-induced testosterone secretion and decreases fRLX expression. Taken together these results strongly indicate that melatonin acts on Leydig cells in the testis of the frog Rana esculenta.


1987 ◽  
Vol 112 (2) ◽  
pp. 311-NP ◽  
Author(s):  
H. D. Nicholson ◽  
R. T. S. Worley ◽  
S. E. F. Guldenaar ◽  
B. T. Pickering

ABSTRACT An oxytocin-like peptide is present in the interstitial cells of the testis, and testicular concentrations of oxytocin have been shown to increase seminiferous tubule movements in vitro. We have used the drug ethan-1,2-dimethanesulphonate (EDS), which depletes the Leydig cell population of the adult rat testis, to examine further the relationships between the Leydig cell, testicular oxytocin and tubular movements. Adult rats were injected i.p. with a single dose of EDS (75 mg/kg) or of vehicle (25% dimethyl sulphoxide). Histological study 3 and 10 days after treatment with EDS showed a reduction in the number of interstitial cells, and levels of oxytocin immunoreactivity were undetectable by radioimmunoassay. Immunostaining revealed very few oxytocin-reactive cells. Spontaneous contractile activity of the seminiferous tubules in vitro was also dramatically reduced, but could be restored by the addition of oxytocin to the medium. Four weeks after EDS treatment, the interstitial cells were similar to those in the control animals both in number and in immunostaining; immunoassayable oxytocin was present and tubular movements were normal. The EDS effect, seen at 3 and 10 days, was not altered by daily treatment with testosterone. However, repopulation of the testes with oxytocin-immunoreactive cells was not seen until 6 weeks in the testosterone-treated animals. We suggest that the Leydig cells are the main source of oxytocin immunoreactivity in the testis and that this oxytocin is involved in modulating seminiferous tubule movements and the resultant sperm transport. The results also imply that testosterone does not play a major role in controlling tubular activity in the mature rat. J. Endocr. (1987) 112, 311–316


Endocrinology ◽  
1988 ◽  
Vol 123 (6) ◽  
pp. 2906-2915 ◽  
Author(s):  
D. S. KEENEY ◽  
S. M. L. C. MENDIS-HANDAGAMA ◽  
B. R. ZIRKIN ◽  
L. L. EWING

1999 ◽  
Vol 162 (1) ◽  
pp. 49-56
Author(s):  
S Subramanian ◽  
PR Adiga

Leydig cells isolated from adult rats and maintained under defined conditions in culture secrete a protein of molecular weight (Mr) 70 000 which is immunologically similar to chicken thiamin carrier protein (TCP). Synthesis of immunoreactive TCP by these cells is demonstrated by immunoprecipitation of [35S]methionine incorporated, newly synthesized proteins with monoclonal and polyclonal antibodies to chicken TCP. The amount of immunoreactive TCP secreted into the culture supernatant is quantitated by using a specific radioimmunoassay. Under the influence of LH, secretion of immunoreactive TCP is enhanced 3-fold and can be inhibited by up to 70% with aromatase inhibitor (1,4,6-androstatrien-3,17-dione). Cyclic AMP acts as a second messenger in the sequence of events involved in LH-induced elevation of immunoreactive TCP in Leydig cells. The effects of exogenous estradiol-17beta and diethylstilbestrol are comparable in terms of stimulation of secretion of immunoreactive TCP by these cells. Tamoxifen brought about a 70% decrease in the elevated levels of immunoreactive TCP. These results suggest that estrogen mediates immunoreactive TCP induction in hormonally stimulated adult rat Leydig cells.


1984 ◽  
Vol 107 (1) ◽  
pp. 110-116 ◽  
Author(s):  
L.J. Wilton ◽  
D. M. de Kretser

Abstract. The influence of circulating LH levels on Leydig cells from cryptorchid adult rats was examined after ablation of the pituitary. After 2 weeks cryptorchidism, serum FSH and LH levels rose 2-fold while serum testosterone (T) remained unchanged. Leydig cells were hypertrophied and showed an increased response to in vitro hCG stimulation. Two weeks after hypophysectomy (hypox), serum hormone levels (LH, FSH and T), Leydig cell size, cytoplasm, organelle content and in vitro T production were all dramatically reduced. However, when hypophysectomy was combined with cryptorchidism (hypox/crypt), there was an increase in Leydig cell size, compared to hypophysectomy alone, in the presence of very low levels of serum FSH, LH and T. Compared to the hypophysectomised state, the mitochondria were larger and the cytoplasm contained more smooth endoplasmic reticulum. The response of the hypox/crypt testes to in vitro hCG stimulation, though significantly less than the cryptorchid testes, was significantly greater than the hypox testes. These results demonstrate that the changes observed in the Leydig cell after cryptorchidism can occur in the absence of peripheral pituitary hormones and are consistent with the hypothesis that a local feedback loop exists within the testis.


2013 ◽  
Vol 136 (2) ◽  
pp. 382-391 ◽  
Author(s):  
Anita C. A. Dankers ◽  
Maarke J. E. Roelofs ◽  
Aldert H. Piersma ◽  
Fred C. G. J. Sweep ◽  
Frans G. M. Russel ◽  
...  

2014 ◽  
Vol 1 ◽  
pp. 271-283 ◽  
Author(s):  
Maarke J.E. Roelofs ◽  
A. Roberto Temming ◽  
Aldert H. Piersma ◽  
Martin van den Berg ◽  
Majorie B.M. van Duursen

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