Ischemia reperfusion myocardium injuries in type 2 diabetic rats: Effects of ketamine and insulin on LC3-II and mTOR expression

Abstract

Objectives: Myocardiopathy occurs in ischemia-induced injury caused by dysregulation of autophagy of cardiac tissues. The present report evaluates the protective effect of ketamine and insulin against myocardial injury in type 2 diabetic rats (T2DM). Methods: The effects of ketamine and its combination with insulin on biochemical parameters and inflammatory cytokines in the serum of I/R-induced myocardial injury in T2DM rats were evaluated. The parameters of reactive oxygen species and the expression of autophagosome signaling pathway proteins were also determined. Using transmission electron microscopy, we investigated autophagosomes. Western blots were used to detect autophagy-associated signaling pathways. Myocardial function was determined by echocardiography and histopathological changes in myocardial tissues were also determined in I/R-induced myocardial injury in type 2 diabetic rats. Results: There was a significant reduction in glucose, AST, LDH, and CK-MB levels and cytokines (IL-1β, IL-6, and TNF-α) in serum of the ketamine ( p < .05) and ketamine + insulin ( p < .01) groups than in the diabetic + I/R. MDA and ROS levels were reduced with a substantial ( p < .05) increase in GSH levels through improved cardiac function in the ketamine ( p < .05) and ketamine + insulin ( p < .01) groups than the diabetic + I/R group. There was an increase in mature autophagosomes in diabetic+I/R+Kt+In compared to diabetic+I/R+Kt alone in infarction and marginal zones. It should be noted that the significant increase ( p < .01) in protein levels of the autophagy-associated intracellular signaling pathways AMPK and mTOR, as well as an increase in LC3-II and BECLIN-1, suggests that ketamine combined with insulin-activated autophagy-associated intracellular signaling AMPK and mTOR. Conclusion: The findings of the study suggest that ketamine combined with insulin administration remarkably protects I/R-induced myocardial injury in rats with T2DM by reducing the dysregulation of autophagy.