Dose response of plasma insulin and glucagon to intravenous n-butyrate infusion in sheep.

n-Butyrate (0, 1, 2, 4, 8, 16, 32, and 64 mumol.kg BW-1.min-1) was infused i.v. for 30 min to investigate the physiological effects of n-butyrate on plasma insulin and glucagon responses in sheep. Blood n-butyrate concentrations during n-butyrate infusion increased (P < .01) with increasing infusion rates. At the greater infusion rates of n-butyrate, plasma glucose concentrations increased (P < .01) during infusion, and then they decreased (P < .05) to less than the preinfusion values. Plasma insulin concentrations increased (P < .01) dose-dependently during n-butyrate infusion at rates of > or = 2 mumol.kg BW-1.min-1. Plasma glucagon concentrations increased (P < .05) during n-butyrate infusion at rates of 32 and 64 mumol.kg BW-1.min-1. It is possible that, in sheep, n-butyrate may have a physiological role in controlling insulin secretion; however, it does not seem to have a role in glucagon secretion.