Effect of graded intravenous doses of urogastrone on duodenal bicarbonate secretion in conscious rats: evidence of a dose-response pattern.

In the present study, the effect of graded intravenous bolus injections of urogastrone, 0.5, 5, 25 and 50 micrograms/kg, on rat duodenal bicarbonate secretion was investigated. Perfused duodenal loops were prepared in rats in a strictly controlled fashion. After full recovery, different groups of rats were injected with intravenous graded bolus doses of urogastrone. During the following 45-min study period, duodenal pH and pCO2 were measured at 5-min intervals and bicarbonate secretion was calculated accordingly. Compared to controls, each dose of urogastrone caused a significant dose-response increase in duodenal bicarbonate secretion, measured either at each 5-min reading or as total 45-min output. These results provide the evidence that urogastrone may play a role in the humoral control of duodenal alkaline secretion.