scholarly journals Enhancement of long-term testosterone secretion and steroidogenic enzyme expression in human Leydig cells by co-culture with human Sertoli cell-enriched preparations

2005 ◽  
Vol 21 (3) ◽  
pp. 129-140 ◽  
Author(s):  
H. LEJEUNE ◽  
P. SANCHEZ ◽  
J. M. SAEZ
Keyword(s):  
Sertoli Cell ◽  
Leydig Cells ◽  
Enzyme Expression ◽  
Steroidogenic Enzyme ◽  
Testosterone Secretion

scholarly journals Effects of Insulin-Like Growth Factor I on Steroidogenic Enzyme Expression Levels in Mouse Leydig Cells

Endocrinology ◽  
2003 ◽  
Vol 144 (11) ◽  
pp. 5058-5064 ◽  
Author(s):  
Gui-Min Wang ◽  
Peter J. O’Shaughnessy ◽  
Curtis Chubb ◽  
Bernard Robaire ◽  
Matthew P. Hardy
Keyword(s):  
Growth Factor ◽  
Leydig Cells ◽  
Insulin Like Growth Factor ◽  
Enzyme Expression ◽  
Steroidogenic Enzyme ◽  
Expression Levels ◽  
Factor I ◽  
Growth Factor I

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
Keyword(s):  
Cell Volume ◽  
Leydig Cell ◽  
Leydig Cells ◽  
Cell Number ◽  
Implant Removal ◽  
Adult Rats ◽  
Testosterone Secretion ◽  
Lh Secretion

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

scholarly journals hCG-induced endoplasmic reticulum stress triggers apoptosis and reduces steroidogenic enzyme expression through activating transcription factor 6 in Leydig cells of the testis

2012 ◽  
Vol 50 (2) ◽  
pp. 151-166 ◽  
Author(s):  
Sun-Ji Park ◽  
Tae-Shin Kim ◽  
Choon-Keun Park ◽  
Sang-Hee Lee ◽  
Jin-Man Kim ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Transcription Factor ◽  
Er Stress ◽  
Transient Expression ◽  
Leydig Cells ◽  
Enzyme Expression ◽  
Steroidogenic Enzymes ◽  
Steroidogenic Enzyme ◽  
Activating Transcription Factor ◽  
High Level

Endoplasmic reticulum (ER) stress generally occurs in secretory cell types. It has been reported that Leydig cells, which produce testosterone in response to human chorionic gonadotropin (hCG), express key steroidogenic enzymes for the regulation of testosterone synthesis. In this study, we analyzed whether hCG induces ER stress via three unfolded protein response (UPR) pathways in mouse Leydig tumor (mLTC-1) cells and the testis. Treatment with hCG induced ER stress in mLTC-1 cells via the ATF6, IRE1a/XBP1, and eIF2α/GADD34/ATF4 UPR pathways, and transient expression of 50 kDa protein activating transcription factor 6 (p50ATF6) reduced the expression level of steroidogenic 3β-hydroxysteroid dehydrogenase △5-△4-isomerase (3β-HSD) enzyme. In an in vivo model, high-level hCG treatment induced expression of p50ATF6 while that of steroidogenic enzymes, especially 3β-HSD, 17α-hydroxylase/C17–20 lyase (CYP17), and 17β-hydrozysteroid dehydrogenase (17β-HSD), was reduced. Expression levels of steroidogenic enzymes were restored by the ER stress inhibitor tauroursodeoxycholic acid (TUDCA). Furthermore, lentivirus-mediated transient expression of p50ATF6 reduced the expression level of 3β-HSD in the testis. Protein expression levels of phospho-JNK, CHOP, and cleaved caspases-12 and -3 as markers of ER stress-mediated apoptosis markedly increased in response to high-level hCG treatment in mLTC-1 cells and the testis. Based on transmission electron microscopy and H&E staining of the testis, it was shown that abnormal ER morphology and destruction of testicular histology induced by high-level hCG treatment were reversed by the addition of TUDCA. These findings suggest that hCG-induced ER stress plays important roles in steroidogenic enzyme expression via modulation of the ATF6 pathway as well as ER stress-mediated apoptosis in Leydig cells.

Aromatase and 11β-hydroxysteroid dehydrogenase 2 localisation in the testes of pigs from birth to puberty linked to changes of hormone pattern and testicular morphology

2008 ◽  
Vol 20 (4) ◽  
pp. 505 ◽  
Author(s):  
A. Wagner ◽  
R. Claus
Keyword(s):  
Blood Plasma ◽  
Sertoli Cell ◽  
Germ Cells ◽  
Leydig Cells ◽  
Hydroxysteroid Dehydrogenase ◽  
Blood Collection ◽  
Testicular Development ◽  
Post Mortem ◽  
Cell Numbers ◽  
Testicular Morphology

Oestrogens and glucocorticoids are important for spermatogenesis and are regulated via aromatase for oestradiol synthesis and 11β-hydroxysteroid dehydrogenase 2 (11β-HSD 2) as an inactivator of cortisol. In the present study postnatal changes of these two enzymes were monitored together with testicular development and hormone concentrations. Pigs were assigned to three periods: Weeks 0–5, Weeks 5–11 or Weeks 11–17. In Period 1, groups of four piglets were killed after each week. Blood plasma and testes were sampled immediately post mortem. For Periods 2 and 3, groups of six pigs were fitted with vein catheters for daily blood collection. Testes from all pigs were obtained after killing. Levels of testosterone, oestradiol, LH, FSH and cortisol were determined radioimmunologically. The 11β-HSD 2- and aromatase-expressing cells were stained immunocytochemically. All hormones were maximal 2 weeks after birth. A rise of LH, testosterone and oestradiol occurred again at Week 17. FSH and cortisol remained basal. Parallel to the first postnatal rise, the presence of aromatase and 11β-HSD 2 in Leydig cells increased, together with germ and Sertoli cell numbers. Expression was low from 3 to 5 weeks, was resumed after Week 5 and was maximal at Week 17. The amount of 11β-HSD 2 in germ cells was greatest at birth, decreased thereafter and was absent after Week 3.

EFFECT OF LONG-TERM INFUSION OF AN LH-RELEASING HORMONE AGONIST ON TESTICULAR FUNCTION IN BULLS

1986 ◽  
Vol 109 (2) ◽  
pp. R9-R11 ◽  
Author(s):  
W. v. Rechenberg ◽  
J. Sandow ◽  
P. Klatt
Keyword(s):  
Treatment Period ◽  
Serum Testosterone ◽  
Constant Infusion ◽  
Continuous Administration ◽  
Entire Treatment Period ◽  
Releasing Hormone ◽  
Testosterone Secretion ◽  
Lhrh Agonists ◽  
Lh Releasing Hormone

ABSTRACT Continuous administration of LH-releasing hormone (LHRH) agonists is an effective method of suppressing testosterone secretion in the male. The effect of the LH-releasing hormone (LHRH) agonist, buserelin, administered to bulls by constant infusion from osmotic minipumps was studied. In one experiment with four treated and one control bull, 109 pg buserelin/day were administered for 22 days. Immediately after implantation, serum testosterone concentrations rose from below 35 nmol/l to 35-105 nmol/l, and all four buserelin-infused bulls showed increased testosterone secretion during the treatment period. After removal of the minipumps, testosterone concentrations decreased to pretreatment levels. In a second experiment bulls were infused for 42 days (four treated and one control), and identical results were obtained. Testosterone secretion was stimulated (52-87 nmol/l serum) during the entire treatment period. These results demonstrate that conditions for stimulation of the pituitary-testicular axis may vary between species. Infusion of low doses of LHRH-agonists in bulls has an extended stimulatory effect without immediate desensitization of gonadotrophin release.

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