RESUMO
In conscious and unrestrained cats the gastric secretion and ulcer formation induced by i.v. infusion of pentagastrin can be inhibited by synthetic salmon calcitonin given simultaneously. The volume and various constituents of gastric juice are proportionally diminished. Pepsin alone is definitely more inhibited, which may be of significance in respect to the mode of action of calcitonin. These effects are dose dependent in the range of 0.01 mug - 1.0 mug/kg/h salmon calcitonin, corresponding to 0.05 - 5.0 MRC units. Based on the finding that such minute doses have effects, it may be speculated that calcitonin has a regulatory function in gastric secretion of cats. In Shay-rats a dose dependent inhibitory effect of salmon calcitonin on ulcer formation and gastric secretion is demonstrated. Besides the volume, the acid concentration of gastric juice is reduced, which may explain the high efficacy of salmon calcitonin to prevent ulcer formation in this species. Ulcerations induced by pylorus ligation, stress and phenylbutazone can be inhibited to a similar degree by calcitonin, suggesting interference with a basal mechanism common to all three types of ulcerogenesis.
