Poly(adenosine diphosphate-ribose) synthetase inhibitor 3-aminobenzamide alleviates cochlear dysfunction induced by...

The present study was undertaken to determine the possible deleterious role played by poly(adenosine diphosphate-ribose) synthetase (PARS) in cochlear ischemia-reperfusion injury. Transient ischemia of the cochlea was induced in albino guinea pigs for 15, 30, or 60 minutes by pressing the labyrinthine artery at the porus acusticus internus. The animals were given intravenous 3-aminobenzamide (a PARS inhibitor) or physiological saline solution I minute before the onset of reperfusion. The compound action potential thresholds were measured before the onset of ischemia and 4 hours after the onset of reperfusion. A statistically significant reduction in the postischemic compound action potential threshold shift was observed in the animals treated with 3-aminobenzamide after 15 or 30 minutes of ischemia, whereas no statistical difference was found after 60 minutes of ischemia. These results suggest that excessive activation of PARS exerts deleterious effects on the cochlear injury induced by transient ischemia.