Impaired secretion of growth hormone in goldthioglucose-obese mice.

Abstract

Goldthioglucose (GTG)-induced hypothalamic obesity in mice is correlated with bilateral destruction of the ventromedial nucleus, the “satiety area,” thus eliminating one of the inhibitory mechanisms to feeding. Pituitary and plasma growth hormone (GH) levels were studied in GTG-obese mice. In 2 separate experiments pituitary bioassayable (BA) GH content was strikingly decreased in GTG-obese mice. In 1 of the 2 experiments, simultaneous determination of pituitary radioimmunoassayable (RIA) GH content while confirming the bioassay data was concomitant with a marked reduction of RIA plasma GH. Thus, both synthesis and release of GH appear to be highly impaired in the obese mice. A 48-hr fasting did not change plasma levels of RIA-GH. These data, while stressing the importance of the neural control over growth hormone secretion in the mouse, suggest that the 2 hypothalamic functions, of which ore controls somatic growth and the other prevents the development of obesity, must be functionally closely interrelat...