Inhibition of Protein Synthesis and Absorption of Lipid into Thoracic Duct Lymph of Rats

Abstract

Summary

Absorption of micellar lipid into thoracic duct lymph of unanesthetized rats was studied after administration of actinomycin D or cycloheximide, agents known to inhibit protein synthesis. Micellar lipid was infused steadily into the upper small intestine to avoid complications by defective gastric emptying or defective lipolysis. Actinomycin D, 50 μg/rat, inhibited mucosal protein synthesis, but absorption of fat into the lymph was unimpaired after this dosage. Malabsorption produced by larger doses of actinomycin D or cycloheximide was accompanied by a marked decline in lymph flow. The change in lymph flow was closely related to decreased recoveries of lipid in the lymph, and reduced flow appeared to be more important than suppression of mucosal protein synthesis. The results indicate that chylomicron formation is not dependent on normal mucosal protein synthesis.