Metabolism of D-Lactate by Tissues of the Ruminant Digestive Tract

Abstract

The metabolism and absorption of D-lactate and D-lactate-U-¹⁴C by tissues of the ruminant digestive tract were investigated using diffusion techniques. Tissue sections from rumen, omasum, abomasum, upper small intestine and colon were studied. Solutions of D-lactate were added to the epithelial side of tissues placed between perspex plates and incubated for 3 hr. in a constant temperature water bath. D-lactate decreased on the epithelial side of all tissues during incubation with a significant increase in concentration of D-lactate on the muscle side of ruminal and small intestinal tissue. Doubling the concentration of D-lactate on the epithelial side of rumen tissue caused a doubling of D-lactate appearing on the muscle side. Significant increases in L-lactate occurred on the epithelial and muscle side of colon tissue. The possibility of a DL-lactate racemase in the tissues is suggested. Small amounts of D-lactate were catabolized to ¹⁴CO₂, by the tissues. The conversion of D-lactate to labeled protein was most noticeable in tissues of the abomasum, small intestine and colon. Copyright © 1973. American Society of Animal Science . Copyright 1973 by American Society of Animal Science.