Effects of exogenous and endogenous bombesin on gastrin secretion from rat antral mucosa in tissue culture.

Effects of exogenous and endogenous bombesin on gastrin secretion were examined using rat antral mucosa in tissue culture. Gastrin secretion was significantly stimulated by exogenous bombesin at a dose of 10(-8) M. Atropine 10(-6) M, which abolished the action of the cholinergic agent carbachol to stimulate gastrin secretion, had no effect on bombesin-stimulated gastrin secretion. In addition, gastrin secretion was significantly inhibited by anti-bombesin antiserum used to block the effect of endogenous bombesin by immunoneutralization. These findings suggest that the stimulation of gastrin secretion by bombesin does not involve cholinergic neural pathways and that endogenous bombesin exerts a continuous stimulation on gastrin secretion in the basal state.