Effects of salmon GnRH and chicken GnRH-II on testicular apoptosis in goldfish (Carassius auratus)

Apoptosis is a form of cell death, characterized by morphological and bioch emical changes. Apoptosis occurs in the normal testis and in response to di fferent agents. In this study, we investigated the effect of gonadotropin-r eleasing hormone (GnRH) in testicular apoptosis in the goldfish. GnRH is a decapeptide that is expressed in different tissues, including gonads in mam malian and non-mammalian species. While GnRH is considered to be a paracrin e mediator of ovarian follicular atresia, the role of GnRH in the testis is less clear. In the present study, treatments with native salmon GnRH and c hicken GnRH-II increased DNA fragmentation (a hallmark of apoptosis) in the mature goldfish testis. On the other hand, gonadotropin hormone was found to act as survival factor, by decreasing spontaneous and GnRH-induced DNA f ragmentation in the goldfish testis. The results demonstrate that GnRH play s an important paracrine role in the control of apoptosis in the goldfish t estis. (C) 2001 Elsevier Science Inc. Ah rights reserved.