Serum free fatty acids, growth hormone, and insulin during trials of ACTH and synthetic subunits.

Abstract

ACTH‐like molecules composed of 24 and 23 amino acid residues administered to healthy men during 3 hours of an intravenous infusion produced increases in serum nonesterified fatty acids; ACTH itself (39 amino acid residues) and molecules comprising 20 or 13 amino acid residues injected in equimolar or greater amounts were inert in this respect. These clear differences are related to the experimental conditions employed, since under other circumstances ACTH is known to increase nonesterified fatty acid levels in man and ACTH and an analogue composed of 20 amino acid residues have the same effect in animals. ln the majority of our trials in man, slow infusion of ACTH or of molecules consisting of 24, 23, or 20 amino acid residues raised the level of immunoassayable growth hormone in serum, but circulating insulin did not change.