Mecamylamine prevents the enhancement of retention induced by lysine vasopressin in mice.
Lysine vasopressin (0.03 microgram/kg, sc) enhanced retention of a one-trial, step-through inhibitory avoidance task when injected into male Swiss mice immediately post-training, as indicated by retention performance 48 h later. A low dose of the vasopressin antagonist, AAVP (0.01 microgram/kg, sc), did not significantly affect retention, whereas a higher dose (0.03 microgram/kg, sc) impaired retention. Neither lysine vasopressin nor AAVP modified latencies to step-through of mice that had not received a footshock during training. The simultaneous injection of AAVP (0.01 microgram/kg, sc) prevented the enhancement of retention induced by lysine vasopressin. The influence of lysine vasopressin on retention was antagonized by the simultaneous administration of mecamylamine (5 mg/kg, sc) but not by hexamethonium (5 mg/kg, sc), atropine (0.5 mg/kg, sc), or methylatropine (0.5 mg/kg, sc). A modulatory role of vasopressin on the activity of central cholinergic nicotinic mechanisms which participate in memory formation is suggested.
Cátedra de Farmacología, Facultad de Farmacia y Biquímica, Universidad de Buenos Aires, Argentina.
C P
CP
Faiman
G A
GA
De Erausquin
C M
CM
Baratti
D000818:Animals; D001127:Arginine Vasopressin / Q000031:analogs & derivatives / Q000494:pharmacology; D001362:Avoidance Learning / Q000187:drug effects*; D001921:Brain / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D008236:Lypressin / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D008297:Male; D008464:Mecamylamine / Q000494:pharmacology*; D008568:Memory / Q000187:drug effects*; D011939:Mental Recall / Q000187:drug effects; D051379:Mice; D011950:Receptors, Cholinergic / Q000187:drug effects; D012153:Retention, Psychology / Q000187:drug effects*
D011950:Receptors, Cholinergic; D001127:Arginine Vasopressin; D008236:Lypressin; D008464:Mecamylamine; C025043:vasopressin, 1-(1-mercaptocyclohexaneacetic acid)-2-(O- methyl-L-tyrosine)-8-L-arginine-