Omega-3 polyunsaturated fatty acids inhibit the accumulation of PAS-positive material in the myocardium of STZ-diabetic wistar rats

This study was conducted to investigate the effect of Omega-3 PUFA on streptozotocin (STZ)-induced diabetic cardiomyopathy in wistar rats. After 4 weeks of STZ (60 mg/kg, i.v.) administration, the diabetic animals were randomly divided into two groups: Diabetic control and Omega-3 PUFA treated diabetic rats. Omega-3 PUFA (0.5 ml/kg) was administered to the latter group for 10 weeks. Age matched normal rats served as Normal controls. During the study, plasma glucose, glycosylated hemoglobin, plasma cholesterol, LDL and HDL cholesterol, triglyerides were evaluated in all the groups. Omega-3 PUFA treatment did not normalise but instead blunted the effect of diabetes with regards to the above parameters significantly (P < 0.01). At the end of the experiment, morphometric and histochemical studies were performed on heart and myocardial enzyme markers were studied. In the diabetic control group, diabetic cardiomyopathy was characerised by elevated CPK (DC 110 +/- 8.85 vs. NC 39 +/- 5.83) and morphological changes in heart. Gravimetric ratios showed increased heart-to-body weight ratio in diabetic control over normal control group. (DC 3.38 +/- 0.05 vs. NC 2.48 +/- 0.03). Histochemical evidence showed increased accumulation of PAS-positive material in myocardial interstitium (++++). The Omega-3 PUFA treatment blunted all these adverse effects of diabetes on heart significantly (P < 0.001). However, further studies are warranted to elucidate the mechanism by which Omega-3 PUFA decreases the accumulation of PAS-positive material in diabetic myocardium. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.