Introduction: Cardiovascular diseases are one of the most common diseases in the world. It is essential to find an efficient natural protective agent against the myocardial damage.
Aim: To determine the protective role of different doses of vitamin E against isoproterenol-induced myocardial damage.
Material and Methods: Fifty adult male albino rats were divided into four main groups: Control group (I), vitamin E-treated group (II) equally divided into 2 subgroups; subgroup (IIa) received Vit E (50mg/kg) and subgroup (IIb) received Vit E (100mg/kg) for one month, isoproterenol-treated group (III) received 3ml normal saline orally for one month and isoproterenol (150mg/kg) intraperitoneally (IP) in the last two days of that month. Vitamin E and isoproterenol-treated group (IV) equally divided into two subgroups; Subgroup (IVa) received vitamin E (50mg/kg) orally for one month and isoproterenol (150mg/kg) IP in the last two days of that month and subgroup (IVb) received vitamin E (100mg/kg) orally for one month and isoproterenol (150mg/kg) IP in the last two days of that month. Heart specimens were processed for light and electron microscopic studies.
Results: Rats injected by isoproterenol developed structural changes in the myocardium in the form of fragmentation of the myofibrils, vacuolated destroyed mitochondria, dilated SER, intracellular and extracellular edema and interstitial mononuclear cellular infiltration. Animals pretreated with vitamin E at a dose of 50mg/kg before injection of isoproterenol revealed minimal protection as they showed myocardial damage similar to isoproterenol-treated group. While animals pretreated with vitamin E at a dose of 100 mg/kg before injection of isoproterenol showed minimal microscopic alterations of the myocardium with preservation of the normal structure of the cardiac myocytes.
Conclusion: Vitamin E at a high dose (100mg/kg) has a protective role on myocardium against isoproterenol- induced myocardial damage.