THE INCORPORATION OF C14 GLYCINE INTO PROTEIN BY HUMAN LIVER SLICES 1

Abstract

Biopsy samples of normal human liver obtained at laparotomy were sliced and incubated with C14-labeled glycine in a modified Krebs-Henseleit buffer and O2. The protein was precipitated with M acetate (pH 4.5), washed, and the fat extracted with alcohol-ether. The dried protein was "plated" and radioactivity measured. Specific activity obtained (S. A.-counts/min./mg.) varied from 160-700 with the complete buffer. There was significant depression of incorporation when Ca or Mg was omitted; S. A. ranged from 10-30 when a simple KC1-KHCO3 medium was used. Uptake was inhibited by N2 or 0.005 [image] cyanide. Rat liver slices yielded protein with S. A. of 250 under the same conditions. Using human sigmoid colon slices protein was obtained having S. A. ranging from 215 to 1175. The incorporation into protein has the characteristics of an enzymatic reaction which may be the process by which the liver synthesizes protein. Since low serum albumin is well correlated with advanced hepatic damage, one might expect to find reduced incorporation using pathological liver slices. Such expts. are in progress.