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Rat Leydig Cells (rat + leydig_cell)
Selected AbstractsEffect of adlay (Coix lachryma-jobi L. var. ma-yuen Stapf.) hull extracts on testosterone release from rat Leydig cellsPHYTOTHERAPY RESEARCH, Issue 5 2009Shih-Min Hsia Abstract Adlay has been used as a traditional Chinese medicine for the treatment of many diseases. However, few studies have reported the effects of adlay seeds on the endocrine system. In the present study, the effects of methanol extracts of adlay hull (AHM) on testosterone synthesis were studied. Rat Leydig cells were incubated with different reagents including human chorionic gonadotropin, 8-bromo-adenosine-3,,5,-cyclic monophosphate, forskolin, A23187, progesterone and androstenedione in the presence or absence of AHM. The rat anterior pituitary (AP) gland was treated with gonadotropin-releasing hormone (GnRH) in vitro in the presence or absence of AHM, and the concentrations of luteinizing hormone (LH) in the media were measured. AHM decreased testosterone release via the inhibition of (1) the PKA and PKC signal transduction pathways, (2) 17, -HSD enzyme activity in rat Leydig cells, and (3) in vitro GnRH-induced LH secretion. Copyright © 2008 John Wiley & Sons, Ltd. [source] Specificity of a new lipid mediator produced by testicular and peritoneal macrophages on steroidogenesisINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 5 2000Lukyanenko Macrophage-derived factor (MDF) is a lipophilic factor produced by rat testicular and peritoneal macrophages that maximally stimulates testosterone production by rat Leydig cells through a steroidogenic acute regulatory protein independent mechanism. The purpose of the present study was to determine whether MDF is also produced by human macrophages, and/or if it acts on human steroidogenic cells. We also studied the tissue-specific functions of MDF by determining if it also acts on steroidogenic cells of the ovary and adrenal glands and, if so, does it require new protein synthesis. It was found that MDF was produced by human peritoneal macrophages, and was capable of stimulating human steroidogenic cells. In terms of tissue specificity, it was found that primary cultures of rat adrenocortical cells respond to MDF with increased secretion of aldosterone and corticosterone, as did rat granulosa cells by producing progesterone. MDF acted in the presence of cycloheximide, indicating that it does not require new protein synthesis. These results indicate that MDF may have significant therapeutic potential and provide a basis for future studies concerning its physiological role in humans. These results further suggest that MDF is not only involved in paracrine regulation of Leydig cells, but also has the potential for the local regulation of steroidogenesis in both granulosa and adrenal cortical cells. [source] Adverse effects associated with persistent stimulation of Leydig cells with hCG in vitroMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 11 2009Archana Aggarwal The detrimental effects of persistent stimulation with hCG were investigated in rat Leydig cells in vitro. Significant rise in lipid peroxidation and reactive oxygen species (ROS) with concomitant attenuation in the activities of antioxidant enzymes: superoxide dismutase, catalase, and glutathione- S -transferase was observed. Transcripts for catalase and superoxide dismutase were also depleted. Subsequent to each hCG challenge, the total antioxidant capacity in the target cells also declined significantly (P,<,0.05). There was an increase in cell apoptosis (23%), which was associated with a rise in caspase-3 activity, PARP cleavage, and Fas, FasL, caspase-8 expression. While Bax and Caspase-9 expression remained unchanged, Bcl-2 demonstrated a marked decline. Taken together, the above data indicate that persistent hCG stimulation of Leydig cells induced adverse effects leading to oxidative stress and apoptosis which was channeled primarily through the extrinsic pathway. Mol. Reprod. Dev. 76: 1076,1083, 2009. © 2009 Wiley-Liss, Inc. [source] Effect of adlay (Coix lachryma-jobi L. var. ma-yuen Stapf.) hull extracts on testosterone release from rat Leydig cellsPHYTOTHERAPY RESEARCH, Issue 5 2009Shih-Min Hsia Abstract Adlay has been used as a traditional Chinese medicine for the treatment of many diseases. However, few studies have reported the effects of adlay seeds on the endocrine system. In the present study, the effects of methanol extracts of adlay hull (AHM) on testosterone synthesis were studied. Rat Leydig cells were incubated with different reagents including human chorionic gonadotropin, 8-bromo-adenosine-3,,5,-cyclic monophosphate, forskolin, A23187, progesterone and androstenedione in the presence or absence of AHM. The rat anterior pituitary (AP) gland was treated with gonadotropin-releasing hormone (GnRH) in vitro in the presence or absence of AHM, and the concentrations of luteinizing hormone (LH) in the media were measured. AHM decreased testosterone release via the inhibition of (1) the PKA and PKC signal transduction pathways, (2) 17, -HSD enzyme activity in rat Leydig cells, and (3) in vitro GnRH-induced LH secretion. Copyright © 2008 John Wiley & Sons, Ltd. [source] Corticosterone induces steroidogenic lesion in cultured adult rat leydig cells by reducing the expression of star protein and steroidogenic enzymesJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 5 2008Srinivasan Rengarajan Abstract The present study was designed to investigate the dose-dependent direct effect of corticosterone on adult rat Leydig cell steroidogenesis in vitro. Leydig cells were isolated from the testis of normal adult male albino rats, purified on discontinuous Percoll gradient and plated in culture plates/flasks overnight at 34°C in a CO2 incubator under 95% air and 5% CO2 using DME/F12 medium containing 1% fetal bovine serum. After the attachment of cells, serum-containing medium was removed and cells were exposed to different doses (0, 50, 100, 200, 400, and 800 nM) of corticosterone using serum-free fresh medium for 24 h at 34°C. At the end of exposure period, cells were utilized for assessment of the activities and mRNA expression of steroidogenic enzymes (cytochrome P450 side chain cleavage enzyme, 3,-hydroxysteroid dehydrogenase, 17,-hydroxysteroid dehydrogenase, and cytochrome P450 aromatase) and steroidogenic acute regulatory protein gene expression. Testosterone and estradiol production were also quantified. Activities of cytochrome P450 side chain cleavage enzyme, 3,- and 17,-hydroxysteroid dehydrogenases were declined significantly in a dose-dependent manner after corticosterone exposure, while their mRNA expression were significantly reduced at higher doses of corticosterone exposure. The activity and mRNA expression of cytochrome P450 aromatase registered a significant increase at 100 nM dose of corticosterone whereas at 200,800 nM doses both the activity as well as the mRNA levels was significantly reduced below the basal level. StAR protein gene expression was significantly inhibited by higher doses of corticosterone employed. At all doses employed, corticosterone significantly reduced the production of testosterone by Leydig cells, while estradiol level registered a significant increase at 50 and 100 nM doses but at higher doses, it registered a significant decrease when compared to basal level. It is concluded from the present in vitro study that the molecular mechanism by which corticosterone reduces the production of Leydig cell testosterone is by reducing the activities and mRNA expression of steroidogenic enzymes and steroidogenic acute regulatory protein. J. Cell. Biochem. 103: 1472,1487, 2008. © 2007 Wiley-Liss, Inc. [source] | |||||||||||||