Plasma insulin and glucagon responses to propionate infusion into femoral and mesenteric veins in sheep.

Propionate (1, 2, 4, 8, 16, 32, and 64 mumol.kg BW-1.min-1 for 30 min) was infused into the femoral and mesenteric veins of adult sheep to investigate the physiological significance of propionate in regulating plasma insulin and glucagon concentrations. The increments in arterial blood propionate concentrations during propionate infusion increased (P < .001) with increasing infusion rates for both infusion sites, and they were smaller (P < .001) for the mesenteric vein infusion than for the femoral vein infusion. Plasma insulin concentrations during propionate infusion increased (P < .10) from preinfusion values with infusion rates of > or = 8 mumol.kg BW-1.min-1 for both infusion sites. The response areas of plasma insulin concentration above basal tended to be smaller (P < .112) for the mesenteric vein infusion than for the femoral vein infusion. Plasma glucagon concentrations during propionate infusion increased (P < .05) from preinfusion values with infusion rates of > or = 8 and 64 mumol.kg BW-1.min-1 for the femoral and mesenteric vein infusions, respectively. The response areas of plasma glucagon concentration above basal were smaller (P < .011) for the mesenteric vein infusion than for the femoral vein infusion. We conclude that in sheep propionate absorbed from the alimentary tract has a physiological role in regulating circulating concentrations of insulin and glucagon.