Endocannabinoids control male reproduction acting at central and local level via cannabinoid receptors. The cannabinoid receptor CB1 has been characterized in the testis, in somatic and germ cells of mammalian and non-mammalian animal models, and its activity related to Leydig cell differentiation, steroidogenesis, spermiogenesis, sperm quality, and maturation. In this short review, we provide ...

unilateral orchidectomy (uo) is required when further breeding potential is important. it is sometimes necessary to remove a single testis in a matured stallion for therapeutic reasons. in this study, twelve donkeys were used to evaluate three techniques of unilateral castration, histological and morphological changes on the remaining testis. results of the study showed that each of the surgica...

Previous studies have shown that testosterone production by the Leydig cells of aged Brown Norway rats is reduced from the relatively high levels produced by Leydig cells of young rats and that this reduction is not secondary to decreased serum luteinizing hormone concentration. The free radical theory of aging proposes that imbalance between pro-oxidants and the antioxidant defense system ulti...

The mechanism of phytoestrogen action in gonadal cells of ganders has not been elucidated. The aim of the study was to investigate in Biłgoraj ganders the possibility of phytoestrogen action via estrogen or androgen receptors or via protein tyrosine kinase pathways in Leydig cells. Genistein and daidzein (5 and 50 microM) as well as equol (50 microM) inhibited testosterone (T) secretion by incu...

The studies presented herein were done to investigate the effects of drug-induced hypocholesterolemia and chronic hormonal stimulation on cholesterol metabolism and steroid biosynthesis in a functional Leydig cell tumor. It was found that 4-aminopyrazolo(3,4-d)-pyrimidine (4-APP)-induced hypocholesterolemia had no effect on a) the amount of cholesterol present in the tumor, b) cholesterol biosy...

Steroid sulfatase (STS) activity was studied in the Long-Evans rat testis. The rate of dehydroepiandrosterone sulfate (DHA-S) hydrolysis determined in whole testis homogenates was low compared to that of the corresponding microsomal fractions, which was, in contrast, as high as that expressed in homogenates from purified Leydig cells. Such an increment in STS activity between total homogenates ...

Hybridization between a mouse Leydig tumor cell line, MA-10, which produces cyclic AMP and progesterone under human chorionic gonadotropin (hCG) stimulation, and freshly isolated mouse Leydig cells gave rise to 54 hybrid clones, one of which, LK17, was capable of hCG-stimulated testosterone production. Subcloning of this hybrid resulted in the emergence of a subclone, K9, whose testosterone pro...

One of the newer stereological methods, the optical fractionator, was applied to the study of the effects of ageing on the human testis. The estimated total number of Sertoli and Leydig cells per testis in men younger than 30 years were 430×10 (CV = SD/mean = 0.35) and 117×10 (CV = 0.53), respectively, while in men older than 50 years the estimated total Sertoli cell number was 266×10 (CV = 0.4...

Resume Les tumeurs à cellules de Sertoli et Leydig sont des tumeurs sécrétantes rares du mésenchyme et des cordons sexuels. Cependant elles constituent l’une des tumeurs le souvent responsables de syndrome de virilisation. La certitude diagnostique est histologique après la chirurgie et il n’ y'a pas de signe échographie spécifique malgré la forte présomption clinique. Le pronostic comme la plu...

Addition of concentrated rat Sertoli cell conditioned medium (rSCCM) to isolated Leydig cells from immature rats stimulated steroid production more than 13-fold within 4 h. LH-stimulated steroidogenesis was not enhanced by addition of rSCCM. The biological activity of the concentrated rSCCM was higher after incubation of Sertoli cells with FSH, whereas FSH alone did not stimulate steroid produc...