Effect of vitamin C on responses of isolated hearts to B-adrenergic stimulation

ABSTRACT

The aim of this study was to investigate the possible protective action of vitamin C, in different doses against the oxidative damage induced by excessive beta-adrenergic stimulation by isoproterenol on the isolated perfused rat heart in a Langendroff preparation. The finding revealed that vitamin C in all doses used [100 mg, 200 mg and 500 mg] reduces the positive Chronotropic response of beta- adrenergic stimulation. Also, it improves the myocardial flow rate in response to isoproterenol infusion.On the other hand, the inotropic responsiveness to isoproterenol is only abolished [reduced peak developed tension] with the large dose of vitamin C 500 mg. Therefor, the benefits of vitamin C against the deletarious effects of excessive beta- adrenergic stimulation of the heart have been demonstrated, although the disadvantageous actions of the large doses of vitamin C should be safeguarded