The large number of past investigation on extended myocardial protection clearly indicates that cold potassium cardioplegia and topical cooling have limited capabilities. Accordingly, more recent experimental approaches have focused on the
modalities of
reperfusion and their implication on postischemic myocardial recovery. Oxygen may play a crucial role in the development of ischemic and reperfusion injury. Reactive oxygen radicals may be produced during ischemia or reperfusion after incomplete
reduction of molecular oxygen or from other pathway and then induce fatal injury of the heart. The important observation of oxygen-induced myocardial damage during reperfusion has led to the concept of applying oxygen free radical scavengers. So,
this
study is on dietary vitamin C supplementation as antioxidant in rats to determine whether or not they have a higher tolerance against cardiac ischemia-reperfusio injury under Langendorff system.
Male or female Sprague-Dawley rats(190-330g) were randomly separated into two groups. Group A was not treated(n=10). Group B received vitamin C supplement(n=10). Experiment was performed 24 hours after vitamin C 200mg fed orally as injectable
ascorbic
acid.
There were significant differences in contractile parameters between control and vitamin C-treated group. The RLVP(rate of post/prcischemic left ventricular pressure)and Rdp/dt(rate of post/preischemic dp/dt) were significant statistically
between
two
groups(p<0.05). Butj, RHR(rate of post/preischemic heart rate), time to first beat and stabilization were not significant.
In conclusion, pretreatment with the antioxidant, ascorbic acid, was found to preserve left ventricular comractile function. But the precdise mechanism of action of ascorbic acid has not as yet been determined, so further study will be required.
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