METABOLISM OF SMALL INTESTINE. OXYGEN UPTAKE AND L-LACTATE PRODUCTION ALONG LENGTH OF SMALL INSTESTINE OF RAT AND GUINEA PIG

1. 1. Oxygen uptake and L-lactate production from endogenous substrates, and from added glucose or fructose, by rings cut from regions of the small intestine of the rat and guinea pig have been determined using adequate or partial oxygenation. 2. 2. Anaerobic lactate production was also determined. 3. 3. The metabolism of the intestine decreased towards the distal end in the rat but did not vary much in the guinea pig. 4. 4. Oxygen uptake by intestinal rings was not altered appreciably by added substrates. 5. 5. Rat rings formed more lactate from glucose than guinea pig rings. 6. 6. The muscle contributed only 10-20 per cent of the total metabolic activity. © 1968.