Participation of angiotensin II in learning and memory. II. Interactions of angiotensin II with dopaminergic drugs.
The effect of angiotensin II (ATII) and of its interactions with dopaminergic drugs injected post-trial on retention in active avoidance tasks in shuttle-box-trained rats were studied. ATII at doses of 0.10 and 0.50 micrograms administered intracerebroventricularly (i.c.v.) immediately after training improved retention. The dopaminergic receptor agonist apomorphine at a dose of 0.10 mg/kg injected intraperitoneally (i.p.) facilitated retention whereas elymoclavine (a dopaminergic agonist) at a dose of 2.5 mg/kg i.p. had no effect. ATII at a dose of 0.10 micrograms i.c.v. administered after apomorphine 0.10 mg/kg or elymoclavine 2.5 mg/kg exerted a stronger retention-facilitating effect. The dopaminergic receptor antagonist haloperidol at a dose of 1 mg/kg i.p. markedly impaired retention. ATII at a dose of 0.50 micrograms administered after haloperidol (1 mg/kg) did not exercise its retention-facilitating effect. It is concluded that the retention facilitating effects of ATII are realized through interactions with brain dopaminergic transmission.
D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D001362:Avoidance Learning / Q000187:drug effects; D004298:Dopamine / Q000502:physiology*; D004347:Drug Interactions; D004873:Ergolines / Q000494:pharmacology; D006220:Haloperidol / Q000494:pharmacology; D008297:Male; D008568:Memory / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D012153:Retention, Psychology / Q000187:drug effects*
D004873:Ergolines; D000804:Angiotensin II; C007586:elymoclavine; D006220:Haloperidol; D001058:Apomorphine; D004298:Dopamine