Octreotide acetate attenuates bombesin induced gastroprotection

Bombesin prevents gastric injury from acidified ethanol, an effect negated by gastrin receptor blockade. This study was done in conscious female rats (N ≥ 5/group) to ascertain what effect bombesin has on gastrin secretion and determine whether this action and/or bombesin-induced gastroprotection is diminished by the antisecretory agent octreotide acetate, a somatostatin analogue. As shown below, bombesin (60 nmol/kg sc) reduced macroscopic injury to the stomach caused by 1 ml of orogastric acidified ethanol (150 mM HCl/50% ethanol) and increased serum gastrin levels (radiounmunoassay). Administration of octreotide acetate (1 nmol/kg sc) partially reversed both effects of bombesin. Data are mean ±SEM. 30 Minute Pretreatments Gastric Injury (mm²) Serum Gastrin (fmol/ml) Significance (ANOVA) Saline/Saline 109 ± 9 110 ± 10*p < 0.001 vs. Saline/Bombesin 7 ± 2*539 ± 31*Saline/Saline Octreotide/Saline 111 ± 11 103 ± 12**p = 0.001 vs. Octreotide/Bombesin 41 ± 4**271 ± 28**Saline/Bombesin This study indicates that both the gastroprotective actions and release of endogenous gastrin by bombesin are mediated, in part, by a somatostatin sensitive mechanism.