Effect of histamine H2-receptor stimulation on bombesin- and peptone-stimulated gastrin release in man

This study was undertaken to determine whether histamine H2-receptors are involved in the regulation of gastrin secretion in man. Since previous studies on the effect of histamine H2-receptor blockade on gastrin release are conflicting, we have studied the effect of histamine infusion (130 nmol/kg/hr) with simultaneous H1-receptor blockade on gastrin release in healthy male subjects. Intragastric pH was maintained at 4.5 by continuous intragastric titration during all studies. Histamine did not affect gastrin release stimulated by infusion of bombesin (90 pmol/kg/hr) or by a peptone meal. Integrated gastrin secretion during bombesin plus histamine was 767 +/- 151 pmol X min/liter (+/- SEM), compared to 757 +/- 144 pmol X min/liter during bombesin plus saline (not significant), whereas integrated meal-stimulated gastrin release was 1666 +/- 456 pmol X min/liter during histamine and 1856 +/- 492 pmol X min/liter during saline. It is concluded that histamine H2-receptors do not seem to be involved in the regulation of gastrin secretion in man.