Protective Role of L-Carnitine and Tocopherol Against Cold Restraint Stress Induced Gastric Lesions In Streptozotocin–Diabetic Rats

Abstract

In the present study, the influence of cold restraint stress (CRS)-induced gastricdamage in diabetic rats, in relation to the antioxidative system was investigated. Malealbino rats were used in the study, they were divided into 5 groups: i): non stressedgroup, ii): control CRS group, iii) diabetic CRS group (the rats of this group wereinjected with streptozotocin (STZ) 70 mg/kg i.p. and used 4 weeks after induction ofdiabetes with blood glucose levels of >350 mg/dl), iv): STZ L-carnitine pretreatmentgroup (STZ-induced diabetic rat of this group were given L-carnitine 500 mg/kg 30min before CRS) and v): STZ-vitamine E pretreatment group (STZ-induced diabeticrat of this group were given vitamin E 60 mg/kg body wt three weeks before CRS).The last four groups were exposed to CRS, at the end of each experiment, gastricdamage was observed macroscopically. CRS induced gastric lesion, that wasmarkedly exacerbated in STZ diabetic rats, but this aggravation was significantlysuppressed by pretreatment with either L-carnitine or tocopherol (vitamin E)pretreatments. Diabetic rat stomachs showed significantly less glutathione peroxidase(GPX) activity as well as reduced glutathione (GSH) content than normal ratstomachs. In addition, the deleterious influence of diabetes on the gastric ulcerogenicresponse to CRS was significantly mitigated by decreasing lipid peroxidation bypretreatment with either L-carnitine or vitamin E. These results suggest that thegastric mucosa of diabetic rats is more vulnerable to cold restraint–induced injury,and the mechanism may be partly accounted for by impairment of the antioxidativesystem associated with a reduced GPX activity and GSH content. Based on thesedata, the beneficial effects of L-carnitine and vitamin E on CRS-induced mucosalinjury especially in diabetics may be attributed to their antioxidative effects.