Galanin stimulates hCG induced testicular steroidogenesis in adult but not in immature male rats

Abstract

The present study was undertaken to understand the role of galanin on testosterone secretion. Leydig cells from adult (60-80 days old) and immature (21-30 days old) rat testis were incubated with galanin (100 nM), galantide (100 nM) and Human Chorionic Gonadotropin (hCG, 25 I.U.) alone or in combinations and testosterone release was measured. It was observed that in adults, galanin failed to alter the basal testosterone release from the dispersed Leydig cells but potentiated the hCG induced testosterone release significantly. While galantide, prevented this galanin potentiating effect, but it did not alter the hCG alone induced testosterone release. On the other hand, the Leydig cells obtained from immature male rats were sensitive to hCG alone but not to galanin or galantide, both of which failed to alter the hCG induced testosterone release from these cells. Based on these results it can be postulated that galanin's role at the level of the male gonad is age dependent since its potentiating effects on hCG induced testosterone release were visible only in the adult and not in the immature male rats.