Stimulation of gastric somatostatin mRNA abundance by substance P in capsaicin-treated rats.

The spinal afferent neurons serving the stomach influence a variety of different gastric functions that together can be considered protective; it is not known whether the stomach can adapt to the loss of these neurons. We now report that in conscious rats pretreated with capsaicin to lesion small-diameter afferents, but not in control rats, i.v. infusion of substance P for 6 h increased the abundance of mRNA encoding somatostatin in antrum; there was no change in a reference mRNA, glyceraldehyde phosphate dehydrogenase. Substance P had no effect on somatostatin mRNA in the gastric corpus in either control or capsaicin-treated rats. An increased sensitivity of antral somatostatin cells to substance P may be one of the adaptive changes that occurs in the stomach of capsaicin-treated rats.