ABSTRACT
A stress response is a natural reaction by the body against potentially harmful stimuli to enhance the chance for survival. Serious stress can induce organ injury or contribute to diseases, such as gastric ulcers. The aim of the present study was to determine the effects of selenium and vitamin E on gastric mucosal damage, secretions and haemato-biochemical changes due to water-immersion restraint stress (WRS) in Wistar rats. Seventy (70) Male Wistar rats (200-220 gram) were divided in to two main groups, 35 rats each for ulcer and acid secretions studies. Group 1 and 2 were sub-divided each into 5 sub-groups of 7 rats: (I) passive control (non-stress rats) (II) active control (WRS plus distilled water) (III) WRS plus selenium (IV) WRS plus vitamin E (V) WRS plus selenium plus vitamin E. The WRS procedure last for 3.5 hours. Gastric tissues were taken out and investigated macroscopically and histologically to determine mucosal damage. Blood samples were collected through cardiac puncture for haematological and biochemical analyses. Gastric secretion was collected after additional 3 hours of pyloric ligation. The result demonstrated that acute WRS significantly (P < 0.001) increased gastric ulcer and gastric secretion parameters as well as MDA concentration, activities of plasma ALT and AST, plasma Zn concentration, and haemolysis of erythrocytes in different concentration of NaCl. However pre-treatment with selenium and vitamin E individually or in combination significantly lowered the recorded increases, but the decrease were considerable in selenium and vitamin E co-administration. Exposure to WRS for 3.5 hours leads to significant (P < 0.001) decreases in the total plasma protein concentration, activities of CAT, SOD and GSH, Mg concentration, number of neutrophils. Pre-treatment with selenium or vitamin E singly or in combination resulted in significant (P < 0.001) upsurge the observed decrease. This study found no significant (P > 0.05) changes in PCV, RBC, Hb and MCV on exposure to WRS. Pre- viii treatment with vitamin E or selenium singly or combine significantly (P < 0.05) increased some of the values of haematological parameters (PCV, RBC, WBC, Hb, and lymphocytes). It was thus concluded that WRS exposure causes significant alteration in macroscopic, histological structure of the gastric tissue, biochemical, haematological, lipid peroxidative parameters and shift in serum antioxidant balance. However pre-treatment with selenium or vitamin E singly or in combination ameliorate some of the recorded adverse effects of WRS. It was noted that co-administration of selenium and vitamin E have a synergistic effects in restoration of WRS-induced changes.