Nitric oxide synthase inhibitor aminoguanidine potentiates iminodipropionitrile-induced neurotoxicity in rats

This investigation was undertaken to study the effect of nitric oxide synth ase inhibitor, aminoguanidine on iminodipropionitrile (IDPN)-induced neurob ehavioral and vestibular toxicity in rats. The dyskinetic syndrome was prod uced in male Wistar rats by i.p. injections of IDPN (100 mg/kg) for 6 days. Aminoguanidine was administered orally in the doses of 50, 150 and 300 mg/ kg, 60 min before IDPN in three different groups. Control rats received veh icle only, whereas another group was treated with 300 mg/kg of aminoguanidi ne alone (without IDPN). Our results showed that aminoguanidine significant ly and dose dependently exacerbated the incidence and intensity of IDPN-ind uced dyskinetic head movements. Aminoguanidine potentiated IDPN-induced los s of air righting reflex. The histopathological examination of inner ear sh owed aggravation of IDPN-induced degeneration of sensory hair cells in the crista ampullaris by aminoguanidine. These results suggest the role of nitr ic oxide in IDPN-induced neurobehavioral and vestibular toxicity. (C) 1999 Published by Elsevier Science Ireland Ltd. All rights reserved.