Objective: The aim of this study was to evaluate the effects of nicotine on myocardium of newborn rats whose mothers received nicotine during gestation and lactation, by using biochemical and pathological parameters and to evaluate the role of antioxidant enzymes, free oxygen radicals, and lipid peroxidation products which have role in the etiopathogenesis of the nicotine induced injury.

Material and Methods: The experiment was carried out on rats of Spraque-Dawley type. The rats were divided into 3 groups. Group I: Low dose nicotine (1 mg/kg/day, n=10). Group II: high dose nicotine group (6 mg/kg/day, n=10). Group III: Control group (n=10). Nicotine was administered by subcutaneous way and control group received 0.2 cc subcutaneous saline. Four weeks later rats were mated. Nicotine was administered from the beginning to end of third week of lactation, (average 11 week, during pregnancy and lactation). Plasma malondialdehyde, nitric oxide, glutation peroxidase and superoxide dismutase levels were measured at the end of the study. After the sacrification, the levels of myocardial malondialdehyde, nitric oxide, glutation peroxidase and superoxide dismutase levels were analyzed and histopathological examination of myocardial tissue was done by haematoxylin – eosin stain with light microscope.

Results: In group I and II the levels of plasma and tissue malondialdehyde and tissue nitric oxide were higher; whereas the levels of myocardial glutation peroxidase and superoxide dismutase were lower than group III (p<0.05). Heavy cardiomyopathy characterized by swelling in myocardial fibrils, interstitial edema, disorganization and necrosis was determined in Group I and II.

Conclusions: Our results demonstrate the destructive effects of nicotine on myocardium: decrease in myocardial antioxidant enzymes activities and increase in free radicals and lipid peroxidation products which have important roles in the pathogenesis of nicotine - induced myocardial injury.