Effect of Protein Inhibitors on Protein and Amino Acids in Mesenteric Lymph ∗

Abstract

Summary

The effects of the protein antagonists cycloheximide and puromycin upon the transport of amino acids and newly synthesized protein into the mesenteric lymph of the intact rat was investigated. Upon feeding a fatty meal (bovine cream) fortified with leucine-¹⁴C these antagonists depressed the formation of lymph protein with a concurrent increase of amino acids, as measured chemically and by tracing radioactivity of these fractions. The influence of cycloheximide was more lasting than puromycin. These two antagonists affect protein synthesis differently as evidenced by the rates of new protein synthesis and the nature of the amino acids transported by the lymph leaving the upper small intestine.