Blood flow and oxygen consumption in the feline small intestine; responses to artificial distension and intestinal obstruction.
Relations between blood flow and oxygen consumption were studied in denervated and homologously perfused small intestine of the cat. Under "resting" conditions, oxygen uptake was independent of blood flow within rather wide limits, whereas fractional oxygen extraction displayed a highly significant correlation to flow. Upon artificial distension of the bowel, oxygen uptake became a function of blood flow. It is suggested that there may exist an "autoregulation" of oxygen uptake, striving to satisfy theoxygen need of the bowel irrespective of the current blood-flow rate. It is also suggested that this "autoregulation" is abolished upon distension of the bowel. With respect to intestinal obstruction, the continuing distension of simple obstruction causes an inability of the bowell-wall vasculature to extract and consume the oxygen currently needed, probably a result of disturbed "autoregulation" of oxygen uptake. An intervening decompression seems to re-establish "autoregulation" in the obstructed bowel. The present results afford evidence for "autoregulation" of intestinal oxygen uptake. They further suggest deterioration of "autoregulation" in intestinal obstruction and corroborate the previous suggestion that intra-operative decompression of obstructed bowel restores the ability of its capillary circulation to withstand with retained function, renewed increments of strain and distension.
D000818:Animals; D002415:Cats; D007415:Intestinal Obstruction / Q000503:physiopathology*; D007421:Intestine, Small / Q000098:blood supply / Q000502:physiology*; D010101:Oxygen Consumption; D010477:Perfusion; D012039:Regional Blood Flow