Effect of changes in plasma free fatty acids level on secretion of human growth hormone.

growth hormone (HGH) levels was investigated in normal young male subjects. The administration of nicotinic acid with its concomitant lowering of plasma FFA was followed by a rise of plasma HGH. The HGH rise could be inhibited by the simultaneous administration of heparin which prevented the fall of plasma FFA, or by glucose administration. The administration of heparin alone resulted in an increase of plasma HGH also in association with the fall of plasma FFA in the absence of any changes in plasma glucose levels. The rise of plasma HGH failed to occur when plasma FFA was kept elevated or when glucose was given. From these results, it was suggested that the fall of plasma FFA has a stimulatory effect and in turn, the elevated plasma FFA has an inhibitory effect on HGH secretion.