L-glutamine supplementation prevents the development of experimental diabetic cardiomyopathy in streptozotocin-nicotinamide induced diabetic rats

Abstract

The objective of the present investigation was to evaluate the effect of L-glutamine on cardiac myopathy in streptozotocin-nicotinamide induced diabetic rats. Diabetes was induced in overnight fasted Sprague Dawely rats by using intraperitonial injection of streptozotocin (55 mg/kg). Nicotinamide (100 mg/kg, i.p.) was administered 20 min before administration of streptozotocin. Experimental rats were divided into Group I: non-diabetic control (distilled water; 10 ml/kg, p.o.), II: diabetic control (distilled water, 10 ml/kg, p.o.), III: L-glutamine (500 mg/kg, p.o.) and IV: L-glutamine (1000 mg/kg, p.o.). All groups were diabetic except group I. The plasma glucose level, body weight, electrocardiographic abnormalities, hemodynamic changes and left ventricular contractile function, biological markers of cardiotoxicity, antioxidant markers were determined after 4 months after STZ with nicotinamide injection. Histopathological changes of heart tissue were carried out by using H and E stain. L-glutamine treatment improved the electrocardiographic, hemodynamic changes; LV contractile function; biological markers; oxidative stress parameters and histological changes in STZ induced diabetic rats. Results from the present investigation demonstrated that L-glutamine has seemed a cardioprotective activity.

Figure 1. Effect on electrocardiographic parameters.

(A) Non-diabetic control, (B) Diabetic control group, (C) L-glutamine (500 mg/kg) and (D) L-glutamine (1000 mg/kg).

Figure 2. Histopathology of rat heart by hematoxyline and Eosin staining.

NM =  normal myocardium, CE =  cytoplasmic eosinophilia, IN  =  mycardial inflammation, CV =  cytoplasmic vacuolization. (A) Non-diabetic control, (B) Diabetic control group, (C) L-glutamine (500 mg/kg) and (D) L-glutamine (1000 mg/kg).