MODULATION BY POLYAMINES OF γ-GLUTAMYL TRANSPEPTIDASE ACTIVITY AND LACTATE PRODUCTION IN CULTURED SERTOLI CELLS FROM IMMATURE AND ADULT REGRESSED GOLDEN HAMSTER

Abstract

Polyamines are involved in cellular growth and differentiation. To analyze a possible role of polyamines on the regulation of Sertoli cell function, we studied the effect of putrescine, spermidine, and spermine on γ-glutamyl transpeptidase (γ-GTP) activity and lactate production on Sertoli cell cultures obtained from immature and adult-regressed golden hamsters. Sertoli cells were cultured for 7 days. The 72 hour conditioned media obtained on day 6 were used to evaluate lactate levels. Gamma glutamyl transpeptidase activity was determined in the cells harvested on day 7. Cultured Sertoli cells isolated from immature and adult-regressed golden hamsters exhibited a clear morphological response to follicle-stimulating hormone (FSH) and to spermine. Gamma glutamyl transpeptidase activity increased in response to FSH in a dose-dependent manner. Dose-dependent stimulation of lactate production by FSH was also observed. For each functional parameter, a similar ED50 value of FSH stimulation was observed in both groups of animals. Spermine increased basal and FSH-stimulated γ-GTP activity in immature and adult-regressed Sertoli cell cultures. A stimulatory effect of spermidine and putrescine on γ-GTP activity was exclusively observed in adult-regressed Sertoli cell cultures. In Sertoli cells obtained from immature hamsters, spermine exerted a stimulatory effect on basal and FSH-stimulated lactate production.These results suggest that, in addition to the known effects of hormones and paracrine factors, polyamines may influence the functionality of Sertoli cells.