Inhibition of Insulin Degradation by Amino Acids and Related Compounds. ∗

Abstract

Summary

In an in vitro system using in-sulin-I¹³¹ and a special liver preparation which degrades insulin, it has been shown that certain amino acids and related compounds inhibit insulin-I¹³¹ degradation, as measured by the accumulation of trichloracetic acid soluble radioactivity. Marked inhibition was demonstrated using cystine, ergothioneine, 3, 4-dihydroxyphenylalanine, isoleucine, tryptophane, indole-3-acetic acid, and casein hy-drolysate (Amigen). In the concentrations tested no significant inhibition was exerted by glutamine, glycine, β-alanine, asparagine, arginine, serine, threonine, leucine, methionine, histidine, hydroxyproline or tyrosine.