Duodenal bicarbonate secretion induced by human epidermal growth factor in rats is partially mediated by prostaglandins.

In the present study, the effect of graded intravenous infusions of human epidermal growth factor (hEGF) 0.005, 0.05 and 0.25 micrograms/ml, with or without 4 mg/kg i.p. indomethacin pretreatment, on rat duodenal bicarbonate secretion was investigated. Perfused duodenal loops were prepared in rats which were given intravenous infusions of hEGF with or without indomethacin. Duodenal pH and pCO2 were measured at 5-min intervals for 45 min, and bicarbonate secretion was calculated. Compared to control, each dose of hEGF caused a significant dose/response rise of duodenal bicarbonate secretion. Prostaglandin release was abolished by indomethacin pretreatment. Indomethacin-pretreated rats had a significant reduction of bicarbonate secretion which was still higher than in controls. These results provide evidence that duodenal bicarbonate secretion induced by hEGF is only partly accounted for by a prostaglandin-dependent mechanism.