HGF and postnatal testis development.

Hepatocyte growth factor regulates many cellular functions acting through c-met, its specific receptor with tyrosine kinase activity. We have previously reported that in prepubertal rats HGF is secreted in the seminiferous tubules by purified peritubular myoid cells whereas Sertoli cells do not express HGF mRNA. In the present paper we report that HGF is expressed by the myoid cells during the entire postnatal testicular development studied and secreted in the culture medium. On the contrary, in Sertoli cells HGF starts to be clearly detectable by northern blot at 25 days of age. HGF is expressed and secreted by Sertoli cells isolated from 35-day-old rats and is able to increase the levels of c-met expression of the Sertoli cells. Although the role of HGF during the development of the postnatal testis need further research to be clarified, the data here presented indicate that HGF is one of the growth factors regulating mammalian testicular function.