Chlorpromazine inhibits episodic growth hormone secretion in the rat

Effects of chlorpromazine (CPZ) on plasma GH and prolactin levels were observed in conscious rats provided with chronic indwelling right atrial cannulae. The administration of CPZ (200 micrograms/100 g b.w. iv) suppressed episodic plasma GH burst and resulted in significant elevations of plasma prolactin levels. These were also observed in rats in which two types of hypothalamic deafferentation, i.e. anterior and complete, had been carried out. The data suggest that CPZ acts within the medial basal hypothalamus and inhibits episodic plasma GH secretion. In addition, it is inferred that catecholamines are involved in the generation of episodic plasma GH burst.