RESUMEN
Cabergoline is an ergot alkaloid derivative with dopamine agonist activity. The use of cabergoline was associated with significantly increased frequency of heart disease. Green tea has been found to prevent many cardiovascular diseases. To determine whether green tea could have an ameliorative effect against myocardial and valvular injury induced by cabergoline toxicity in rats or not. Thirty-six adult albino rats were used in this study. Medications were administered 6 days/week for 3 months by an oral gavage. The animals were divided into three groups; group 1 served as a control. Group II was given 0.5mg/kg cabergoline dissolved in corn oil. In group III, the rats received green tea 1000mg/kg, dissolved in 3ml distilled water along with cabergoline. Venous blood samples were collected. Cardiac enzymes including serum cardiac troponin I, lactate dehydrogenase, and creatine kinase-MB were estimated. All rats were sacrificed and their hearts were dissected out and processed for light and election microscopic examination. Cabergoline administration caused significant increases in the studied cardiac enzymes compared with the control groups. Histologically, evident myocardial lesions were revealed in group II in the form of widely separated and split muscle fibers. Ultrastructurally, the sarcoplasm contained irregular nuclei and bizarre-shaped mitochondria of different sizes. Localized areas of edema, corrugated sarcolemma, and interstitial collagen fibers were observed particularly in areas of myocardial damage. Alterations in the intercalated disc were also revealed. The mitral valve leaflets showed shortening and thickening of their leaflets. Coadministration of green tea with cabergoline caused a significant decrease in the mean troponin-I serum level compared with the cabergoline-treated group, whereas lactate dehydrogenase and creatine kinase -MB levels did not show any significant changes. Structurally, improvements in most myocardial and mitral lesions in the treated group were detected, except for some bizarre-shped mitochondria and interruption of the intercalated discs. Cabergoline has a deleterious effect on the histological structure of cardiac muscle and valves. Green tea could ameliorate some of these effects