Intestinal capillary exchange capacity and oxygen delivery-to-demand ratio.
The relations between intestinal capillary exchange capacity and various determinants of tissue oxygenation were characterized in autoperfused, denervated preparations of the canine ileum. Ileal metabolic demand was either increased (intraluminal glucose) or decreased (graded reductions in intraluminal temperature) while measuring blood flow, arterial oxygen content, arteriovenous oxygen difference, and the capillary filtration coefficient (an index of capillary exchange capacity). No significant correlations were obtained between the capillary filtration coefficient and 1) blood flow), 2) oxygen delivery, or 3) oxygen demand. The capillary filtration coefficient was directly related to the arteriovenous oxygen difference and inversely related to the oxygen delivery-to-demand ratio. These observations support the hypothesis that intrinsic modulation of oxygen extraction is mediated by vascular elements which govern capillary exchange capacity and that capillary exchange capacity is inversely related to the oxygen delivery-to-demand ratio.
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D002196:Capillaries / Q000502:physiology*; D004285:Dogs; D005374:Filtration; D007082:Ileum / Q000098:blood supply*; D007700:Kinetics; D010100:Oxygen / Q000097:blood*; D010313:Partial Pressure; D012039:Regional Blood Flow
D001786:Blood Glucose; D010100:Oxygen