Bis (2-butoxyethyl) Phthalate Delays Puberty Onset by Increasing Oxidative Stress and Apoptosis in Leydig Cells in Rats / 生物医学与环境科学（英文）

OBJECTIVE@#This study investigated the effects of bis (2-butoxyethyl) phthalate (BBOP) on the onset of male puberty by affecting Leydig cell development in rats.@*METHODS@#Thirty 35-day-old male Sprague-Dawley rats were randomly allocated to five groups mg/kg bw per day that were gavaged for 21 days with BBOP at 0, 10, 100, 250, or 500 mg/kg bw per day. The hormone profiles; Leydig cell morphological metrics; mRNA and protein levels; oxidative stress; and AKT, mTOR, ERK1/2, and GSK3β pathways were assessed.@*RESULTS@#BBOP at 250 and/or 500 mg/kg bw per day decreased serum testosterone, luteinizing hormone, and follicle-stimulating hormone levels mg/kg bw per day (P < 0.05). BBOP at 500 mg/kg bw per day decreased Leydig cell number mg/kg bw per day and downregulated Cyp11a1, Insl3, Hsd11b1, and Dhh in the testes, and Lhb and Fshb mRNAs in the pituitary gland (P < 0.05). The malondialdehyde content in the testis significantly increased, while Sod1 and Sod2 mRNAs were markedly down-regulated, by BBOP treatment at 250-500 mg/kg bw per day (P < 0.05). Furthermore, BBOP at 500 mg/kg bw per day decreased AKT1/AKT2, mTOR, and ERK1/2 phosphorylation, and GSK3β and SIRT1 levels mg/kg bw per day (P < 0.05). Finally, BBOP at 100 or 500 μmol/L induced ROS and apoptosis in Leydig cells after 24 h of treatment in vitro (P < 0.05).@*CONCLUSION@#BBOP delays puberty onset by increasing oxidative stress and apoptosis in Leydig cells in rats.@*UNLABELLED@#The graphical abstract is available on the website www.besjournal.com.

Musk gland seasonal development and musk secretion are regulated by the testis in muskrat (Ondatra zibethicus)

BACKGROUND: The muskrat is a seasonal breeder. Males secrete musk to attract females during the breeding season. The testosterone binding to the androgen receptor (AR) in musk glands of muskrat may play an important role conducting the musk secretion process. METHODS: The musk gland, testis and blood samples of musk rats are collected in both breeding and non-breeding seasons. Some part of the samples are kept in liquid nitrogen for transcriptome analysis and Western blotting test. Some part of the samples are kept in 70% alcohol for histology experiment, blood samples are kept at -20 °C for the serum testosterone measurement experiment. RESULTS: This study demonstrates that the quantity of secreted musk, the volume of the musk glands, the diameter of the gland cells and AR expression are all higher during the breeding season than at other times (p < 0.01). StAR, P450scc and 3ß-HSD expression in the Leydig cells of the testis were also higher during this season, as was serum testosterone. AR was also observed in the gland cells of two other musk-secreting animals, the musk deer and small Indian civet, in their musk glands. These results suggest that the testes and musk glands co-develop seasonally. CONCLUSION: The musk glands' seasonal development and musk secretion are regulated by the testes, and testosterone plays an important role in the seasonal development of musk glands.

Effect of clomiphene citrate on sperm density in male partners of infertile couples.

Infertility is on the rise in today's world. A subnormal sperm count is frequently encountered in infertile couples. Clomiphene citrate, 1-[p-(beta-diethyl aminoethoxy) phenyl]-1,2-diphenyl chloroethylene, is an orally active nonsteroidal agent distantly related to diethylstilbestrol. It is thought to stimulate pituitary gonadotropin release by excluding estradiol from hypothalamic receptor sites. This interaction neutralizes the normal negative feedback control of estrogen and results in enhanced secretion of LH-RH, FSH-RH and gonadotropins. Testosterone is produced by the Leydig cells in response to LH secretion. The concentration of testosterone in the tubular environment is believed to maintain the gametogenic function of the testis. Clomiphene citrate in the dose of 25 mg daily for 25 days with five days rest was administered to 25 extreme oligozoospermic men (group I) and 40 moderate oligozoospermic men (group II) the cycle being continued for three months). Repeat semen analysis was done at the end of three months and all the routine seminal parameters were reevaluated. The data thus obtained was analyzed using Student's paired 't' test. The mean sperm count in Group I increased from 3.84 +/- 0.32 to 8.2 +/- 1.58 (P < 0.05) and in Group II from 13.05 +/- 0.48 to 24.55 +/- 1.73 (P < 0.001). The mean motile sperm count in Group I increased from 1.74 +/- 0.25 to 3.92 +/- 0.83 (P < 0.05) and in Group II from 8.27 +/- 0.40 to 10.05 +/- 0.56 (P < 0.01). Thus clomiphene citrate exerts its effect on spermatogenesis by raising the endogenous serum FSH, LH and testosterone levels to initiate and maintain gametogenesis (10). Researchers opined that this increase in endogenous gonadotrophins manifests itself in improving the sperm count, sperm motility and to certain extent morphology of the sperms, when there is no end-organ pathology.

Immunohistochemical study of osteopontin in boar testis

The expression of osteopontin (OPN) in boar testis was studied. Western blot analysis detected 66- and 32-kDa OPN immunopositive bands in the testes of adult boars. In postnatal piglets, the 66-kDa OPN band was detected in the testes, but not the 32-kDa band. In the newborn testis, OPN immunostaining was seen in gonocytes and in some supporting cells in the seminiferous tubules, as well as in interstitial Leydig cells. In the adult boar testis, OPN immunoreactivity was detected in seminiferous tubules with varying intensities. Intense OPN immunostaining was seen in the residual bodies and acrosomes in the spermatids while, occasionally, OPN immunostaining was seen in spermatogonia and various stage of spermatocytes but in few Sertoli cells in the seminiferous tubules. In addition, Leydig cells in adult boars were weakly immunostained with OPN. These findings suggest that OPN is detected in the majority of germ cells and is involved in spermatogenesis in boar testis.

Expression of caveolin-1 in rat Leydig cells

Caveolin-1, the first member of caveolin family reported, is recognized as the structural component of caveola, a plasma membrane invagination or vesicles that are a subcompartment distinct from clathrin-coated pits. This protein is also known to be involved in cholesterol trafficking. The aim of this study was to determine the expression of caveolin-1 in adult rat Leydig cells. Testis sections incubated with an antibody to caveolin-1 showed, by immunohistochemistry, a moderate number of Leydig cells with different degrees of immunoreaction and a strong reaction in endothelial cells and in the lamina propia of seminiferous tubules.Caveolin- 1 was detected in the cell cytoplasm with a granular pattern and on the cell surface of Leydig cells cultured 24 h on uncoated, laminin-1 or type IV collagen coated coverslips. We also observed a milder reaction in 3 h cultures. Immunoreaction was also detected in Leydig cells with an antibody to tyrosine-phosphorylated caveolin-1. By double immunofluorescent technique, we observed co-localization of caveolin- I and 313-hydroxysteroid dehydrogenase. Western blot analysis revealed a band of about 22 kDa molecular weight that was recognized with both caveolin-1 and tyrosine-phosphocaveolin-1 antibodies. Caveolin-l is one of a few proteins with ademonstrated ability to bind cholesterol in vivo. In this context, the presence of caveolin- in Leydig cells may be related to cholesterol traffic--a rate limiting step in steroid biosynthesis.

Alcohol abuse-duration dependent decrease in plasma testosterone and antioxidants in males.

Ethanol is a testicular toxin and it causes fertility abnormalities with low sperm count and impaired sperm motility in men. The present study was designed to investigate plasma testosterone level and hypothalamic pituitary gonadal (HPG) axis function in alcoholic men and also effect of ethanol on systemic oxidative stress. Forty six male alcohol abusers in the age group 20-40 years were selected. Fifty five, males in the same age group served as control. Alcohol abusers had significantly low plasma testosterone with low luteinizing hormone and follicle stimulating hormone. In addition they had significantly high thiobarbituric acid reactive substances (TBARS), superoxide dismutase and glutathione S-transferase, and low glutathione, ascorbic acid, catalase, glutathione reductase and glutathione peroxidase. Moreover, serum testosterone level in alcoholics negatively correlated with duration of alcohol abuse, and TBARS. Duration dependent decreased serum testosterone level in alcohol abusers might be due to 1) increased oxidative stress which can damage Leydig and supporting Sertoli cells and 2) impaired HPG axis.

FSH, the neglected sibling: evidence for its role in regulation of spermatogenesis and Leydig cell function.

The role of follicle stimulating harmone(FSH) in male reproductive function remains a matter of debate although recent evidences strongly suggest a role despite the controversies that arose following the results obtained with FSH-beta null mice and observations from human FSH receptor mutations. This review summarizes the recent developments of our understanding on the role of FSH in male reproduction. Specifically the results obtained with FSH-beta and FORKO null mice are be discussed in light of our observations employing active and passive neutralization of endogenous FSH in rodents and primates along with other studies. On the basis of results obtained employing a variety of models it can be conclude unequivocally that FSH regulates Leydig cell function and is essential for normal quantitative spermatogenesis.

Interrelationship among testicular cells in wall lizard Hemidactylus flaviviridis (Rüppell): an ultrastructural seasonal and experimental study.

The present study was aimed at investigating ultrastructure of different testicular cells and their interactions through various junctional specializations during different phases of reproductive cycle in wall lizard H. flaviviridis to develop an integrated approach of cell-cell interaction in control of testicular functions. Specialized steroid synthesizing cell organelles such as smooth endoplasmic reticulum (SER) and long slender mitochondria with tubulo-vesicular cristae were predominantly seen in Leydig as well as Sertoli cells during spermatogenically active phase, suggesting their active involvement in steroid biosynthesis. Peritubular cells also exhibited marked seasonal variations. Multi-layered fibroblast-like peritubular cells during regressed phase became single layered myoid-like during spermatogenically active phase. The presence of various types of junctions, including gap and tight junctions (occluding junctions) and adhering junctions such as desmosomes, septate-like junction, ectoplasmic specializations and tubulo-bulbar complexes, were demonstrated among testicular cells in wall lizard H. flaviviridis. However, the nature and degree of junctional (environmental) interaction varied with the reproductive state of the wall lizard. Further, administration of dihydrotestosterone in wall lizards during regressed phase resulted in increase of lipid droplets in Leydig cells and accumulation of germ cell debris in seminiferous tubules. Some of the Sertoli cells were seen darker in response to testosterone treatment probably due to its inhibitory effect on lipid metabolism. These results suggest that testosterone either directly or via inhibiting pituitary basal gonadotropin secretion has suppressive effect on testicular cells.

Melatonin binding sites in interstitial cells from immature rat testes

Melatonin binding sites in rat testes interstitial cells were identified using 2-[125I]-iodomelatonin. Saturation studies of cells revealed a single class of high affinity binding sites, with an apparent equilibrium dissociation constant (Kd) of 100 +/- 20 pM, and a total binding capacity (B max) of 3.0 +/- 0.2 x 10(3) melatonin molecules per cell. Binding was reversible and inhibited by non radioactive melatonin. These results suggest that interstitial cells from immature rat testes have specific receptors for melatonin

A possible role for a low molecular weight peptide in regulation of testosterone production by rat Leydig cells.

Sodium dodecyl sulphate-polyacrylamide gel electrophoresis of Percoll purified Leydig cell proteins from 20- and 120-day-old rats revealed a significant decrease in a low molecular weight peptide in the adult rats. Administration of human chorionic gonadotropin to immature rats resulted in a decrease in the low molecular weight peptide along with increase in testosterone production. Modulation of the peptide by human chorionic gonadotropin could be confirmed by Western blotting. The presence of a similar peptide could be detected by Western blotting in testes of immature mouse, hamster, guinea pig but not in adrenal, placenta and corpus luteum. Administration of testosterone propionate which is known to inhibit the pituitary luteinizing hormone levels in adult rats resulted in an increase in the low molecular weight peptide, as checked by Western blotting. It is suggested that this peptide may have a role in regulation of acquisition of responsiveness to luteinizing hormone by immature rat Leydig cells.

Prolactin effects on testicular interstitial cells in primary cultures

En el presente trabajo se determinaron los efectos de la prolactina (PRL) "in vitro" sobre la esteroidogénesis testicular, utilizando un cultivo primario de células intersticiales de rata inmadura. Las células fueron cultivadas en un medio químicamente definido, con el agregado de insulina y transferrina durante 2 días a 34§C. La producción de andrógenos durante el segundo día de cultivo resultó ser significativamente mayor que en el primer día (3 alfa-Androstandiol (3 alfa-Diol) 5.14 ñ 0.46 vs. 3.74 ñ 0.10 ng/microng ADN, p < 0.001); Testosterona (T) + Dihidrotestosterona (DHT) 0.40 ñ 0.04 vs. 0.34 ñ 0.03 ng/microng ADN, p < 0.001). La curva dosis respuesta para distintas dosis de hCG mostró un ED50= 2.5 mUI/ml. El efecto agudo de la PRL (10, 100 y 1000 ng/ml) sobre la producción basal de 3 alfa/Diol se evaluó luego de 45 h de cultivo. Sólo la dosis de PRL de 1000 ng/ml reveló diferencias significativas con respcto al control y dicho efecto pordría ser debido a su contaminación con LH. En otra serie de experimentos se evaluaron los efectos de menores dosis de la hormona a tiempos prolongados. La PRL (10 ng/ml), agregada durante todo el tiempo de cultivo, causó una inhibición significativa en la producción basal de 3 alfa-Diol, mientras que la respuesta a un estímulo máximo con hCG no varió. Cuando se determinó la producción de T+DHT se observó un cambio notorio en la relación T+DHT/Diol, tanto en condiciones basales (Control: 0.09 vs. PRL: 0.38) como ante el estímulo con hCG...

Degradación de gonadotropina corioníca humana unida a receptores en células de leydig / Degradation of receptor-bound human chrionic gonadotrophin in leyding cells

Se determina la cinética de degradación de la 125-hCG unida a su receptor en células de Levding, aisladas de ratas maduras. Se analiza el efecto de la temperatura y de agentes lisosomotrópicos sobre la velocidad de degradación del complejo H-R. Se comparan estos resultados con los reportados en la literatura, los cuales se refieren a células de Leyding tumorales de ratón