ROLE OF SPASMOLYTIC POLYPEPTIDE IN HEALING OF STRESS-INDUCED GASTRIC-LESIONS IN RATS

Stress is known to induce gastric ulcerations but the mechanism of the ir healing has been little studied. This paper describes the studies o n mucosal expression and the effect on ulcer healing of spasmolytic pe ptide (SP), one of the members of the trefoil peptide family. Gastric ulcerations were induced in rats by the exposition to 3.5 h of water i mmersion and restraint stress. It was found that the number of these l esions gradually declined at 4, 8 and 12 h after stress and this spont aneous healing was significantly accelerated by s.c. infusion of human recombinant SP in a constant dose of 50 mu g kg(-1) h(-1). The healin g of the stress-induced ulcerations was accompanied by a gradual resto ration of gastric mucosal blood flow and the decrease in gastric acid and pepsin secretion towards the normal values. The expression of SP i n rats (rSP) was detected by RT-PCR in the intact mucosa and during al l tested time periods reaching a peak al 4 h after the stress. Immunos taining for rSP in the intact mucosa was confined to the mucous neck c ells, but following the exposure to stress it was significantly enhanc ed and occurred also in the cells of the basal region of gastric gland s, reaching a peak at 4 h after the stress. We conclude that SP plays an important role in healing of stress-induced gastric lesions possibl y by the acceleration of the mucosal repair, the enhancement of mucosa l blood flow and the inhibition of gastric secretion. (C) 1997 Elsevie r Science B.V.