Genesis of episodic growth hormone secretion.

The secretion of growth hormone (GH) is governed by the remarkably complex interaction of neural and feedback regulatory components. The net result is a striking pulsatile pattern of GH release evident in every mammalian species studied so far. Extensive experimental evidence indicates that the episodic pattern of GH release from the pituitary gland is generated by a delicate interplay between at least two hypothalamic hormones--a stimulatory GH-releasing factor (GRF) and an inhibitory hormone, somatostatin (SRIF). This paper will focus on the interrelation of GRF and SRIF, and on the modulatory influence of GH and insulin-like growth factor (IGF) feedback, in the genesis of episodic GH secretion.