Plasma gastrin levels during oral glucose tolerance test and insulin tolerance test in acromegaly

Abstract

This study has shown that there were not any significant increments (during ITT) or decrements (during OGTT) of plasma gastrin values in patients with acromegaly. Neither did gastrin response to ITT or OGTT differ in patients who had hyperprolactinaemia also. There is experimental evidence for increased concentration of gastrin in blood following insulin injection and for reduced concentration in the presence of hyperglycaemia. The release of gastrin depends both on the degree of hypoglycaemia achieved and the adrenergic response provoked as shown by Frier, Cirall, Adrian and Bloom (1982). There is no clear evidence however that these agents are involved in the physiological control of gastrin release (Blair, Grund, Kay, Lund, Reed, Sanders, Thompson and Venables 1978). The fact that gastrin circulates in a number of different molecular forms with different biological potencies further complicates the interpretation.