Dopamine D4 receptor antagonist L745,870 abolishes cognitive effects of intracerebroventricular angiotensin IV and des-Phe(6)-Ang IV in rats.
In this study effect of L745,870, a selective D(4) dopamine (DA) receptor blocker, on the pro-cognitive action of intracerebroventricularly (icv) injected angiotensin IV (Ang IV) and des-Phe(6)-Ang IV was examined. Male Wistar rats weighing 180-200 g were used. Both peptides given at the dose of 1 nmol facilitated recall of a passive avoidance (PA) behaviour, improved object recognition (OR) memory, decreased number of errors, increased number of sequential correct entries and shortened time-to-goal in an eight-arm radial maze (RM). In the auxiliary tests performed to control for the participation of unspecific motor (open field, OF) and emotional ('plus' maze, PM) effects of our treatment in the results of memory tests they had either no (OF) or negligible (PM) effects. Intraperitoneal pretreatment of the animals with 1 mg/kg of L745,870 abolished effects of both peptides on PA and OR and slightly diminished those observed in the eight-arm RM.
Department of Clinical Pharmacology, Medical University of Bialystok, Waszyngtona 15A, 15-274 Bialystok, Poland. braszko@umwb.edu.pl
Jan J
JJ
Braszko
D000804:Angiotensin II / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000494:pharmacology; D000818:Animals; D001007:Anxiety / Q000523:psychology; D001362:Avoidance Learning / Q000187:drug effects; D003071:Cognition / Q000187:drug effects*; D003627:Data Interpretation, Statistical; D018492:Dopamine Antagonists / Q000494:pharmacology*; D005106:Exploratory Behavior / Q000187:drug effects; D005556:Form Perception / Q000187:drug effects; D007276:Injections, Intraventricular; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D011939:Mental Recall / Q000187:drug effects; D009043:Motor Activity / Q000187:drug effects; D011725:Pyridines / Q000494:pharmacology*; D011758:Pyrroles / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D050638:Receptors, Dopamine D4 / Q000037:antagonists & inhibitors*; D021641:Recognition, Psychology / Q000187:drug effects
C099630:3-((4-(4-chlorophenyl)piperazin-1-yl)methyl)-1H-pyrrolo(2,3-b)pyridine; D018492:Dopamine Antagonists; D011725:Pyridines; D011758:Pyrroles; C496150:angiotensin IV, des-Phe(6)-; D000804:Angiotensin II; D050638:Receptors, Dopamine D4; C012877:angiotensin II, des-Asp(1)-des-Arg(2)-Ile(5)-