Possible mediation by luminal somatostatin of bombesin-induced satiety in the cat.

Intravenous bombesin produced a dose-related stimulation of luminal gastric somatostatin output and a concomitant dose-dependent inhibition of food intake in the gastric fistula cat. Maximal food intake inhibition was observed at 1,280 pmol.kg-1.h-1 and corresponded to 65 +/- 7% (P less than 0.01). These effects of bombesin were dose dependently abolished by the specific bombesin-receptor antagonist, [Leu13-psi(CH2NH)-Leu14]bombesin. Furthermore, intragastric administration of somatostatin-14, at doses corresponding to those found in the gastric lumen in response to intravenously administered bombesin, significantly inhibited the first 30 min of food intake. This administration had however no effect on total (daily) food intake. We therefore suggest that luminal gastric somatostatin could at least account for bombesin-induced short-term satiety.