Regulation of oxygen uptake in resting and pentagastrin-stimulated canine stomach

The relation between oxygen uptake and blood flow in the isolated dog stomach was investigated under resting conditions and during intra-arterial infusion of isoproterenol or pentagastrin. Blood flows above and below control values were achieved by pump perfusion and partial arterial occlusion, respectively. In the resting stomach oxygen uptake increased from 0.4 to 1.5 ml.min-1.100 g-1 as blood flow increased from 4 to 40 ml.min-1.100 g-1 and then remained constant for blood flows up to 100 ml.min-1.100 g-1. Isoproterenol did not significantly alter the relation between oxygen uptake and blood flow. In pentagastrin-stimulated stomachs oxygen uptake was maintained at 2.5 ml.min-1.100 g-1 at blood flows between 40 and 100 ml.min-1.100 g-1 and decreased at blood flows below 40 ml.min-1.100 g-1. The results indicate that pentagastrin increases oxidative metabolism in the stomach. Despite this increase in oxygen consumption with pentagastrin, the general shape of the relation between blood flow and oxygen uptake remained the same and was simply displaced vertically above the control data.