Objective: To study the precise cause and the specific procedure about gastric mucosal lesion in rats with water immersion-restraint stress(WRS).
Methods: One hundred and forty-four Wistar rats were divided into 9 groups randomly: A, B, C, D, E, F, G, H and I group. There were 16 rats in each group. A, B and C groups underwent gastric emptying determination. Emptying rate of gastric fluid was determined with radiate nuclide (99m)Tc. D, E and F groups underwent gastric acid secretion determination after cleaning gastric contents and pylorus ligation. G, H and I groups underwent gastric acid secretion determination after pylorus ligation without cleaning gastric contents. Gastric mucosal lesion ulcer index(UI) was evaluated. The relationship between of gastric mucosal lesion and gastric emptying rate and gastric acid secretion were examined.
Results: Gastric emptying rate decreased obviously when the WRS time was prolonged. There were significant differences among B (WRS 2 h), C group (WRS 4 h) and A group (controlled group) (P<0.01). There was also significant difference between B and C group (P<0.01).The rats' gastric acid secretion was inhibited significantly. The differences among E (WRS 2 h), F (WRS 4 h) and D groups (controlled group) were significant (P<0.01). There was no significant difference between F and E groups (P>0.05). The gastric mucosal lesions were aggravated with time of stress. Gastric contents cleaning could effectively prevent gastric mucosal lesions originated by stress .The operation had no influence on this test. There were significant gastric mucosal lesion UI in B and C groups compared with A group (P<0.01). The difference between B and C group was significant (P<0.01).There were no gastric mucosal lesions in A, D, E, F and G groups. However, There was significant difference between I and F group (P<0.01). No significant difference were found among A, D, E, F and G groups (P>0.05). There were significant difference between H and B group and also between I and C group (P<0.01).
Conclusions: WRS can induce gastric emptying disturbance, reduce gastric acid secretion and cause gastric mucosal lesion. As a factor inducing gastric mucosal lesion, acid can damage gastric mucosa as long as it exists without necessary peracid. The prolongation of acid with gastric mucosa contact period and the decrease of gastric mucosa resistance are perhaps the major causes of gastric mucosal lesion. Besides anti-acid, giving facilitative gastric emptying drugs and gastric lavage during stress ulcer prevention and cure should be considered. Acid evacuation in time is also a major cure for gastritis and recurrent ulcer.