[Effects of insulin-like growth factor-1 on the regulation of hypothalamus-hypophysis-testis axis].

It has been demonstrated that insulin-like growth factor-1 (IGF-1) stimulates the proliferation and division of cells, facilitates the individual growth and development and regulates the material metabolism. Furthermore, it regulates male reproductive development and testicular endocrine functions. IGF-1 can stimulate the expression of GnRH gene in the hypothalamus of prepubertal male mice. However, it has no effect on or even inhibits GnRH gene expression in adult mice. IGF-1 may influence the growth, maturation and differentiation of GnRH neurons. It also accelerates LH and FSH secretion in hypophysis. IGF-1, produced locally in the testis and combined with its specific receptor, can regulate the proliferation and differentiation of adult Leydig cells, cause Sertoli cells to play different functions and control the biosynthesis of testicular hormones.