Influence of sodium nitroprusside "NO-donor" on psychotropic activity of angiotensin II.

In this work we compared the influence of sodium nitroprusside [SNP] (a NO donor) on behavioural effects of angiotensin II [AII] in rats. The motility, stereotypy, learning of conditioned avoidance responses and recall of passive avoidance behaviour allowing to avoid aversive stimulation were estimated. The intracerebroventricularly injection--15 min before the experiment--of AII, SNP and AII combined with SNP did not produce changes in psychomotor activity in open field, not significantly accelerated acquisition of conditioned avoidance responses and significantly improved recall of the passive avoidance. AII, SNP and AII with SNP applied immediately before the experiment intensified stereotypy evoked by apomorphine in the dose of 1 mg/kg and amphetamine in the dose of 7.5 mg/kg given intraperitoneally. These results show that; 1) sodium nitroprusside as a donor NO participates in memory and learning processes, 2) overproduction of NO did not change behavioural effects of AII in these experiments.