[Effects of cis-N-(1-benzyl-2-methylpyrrolidin-3-yl)-5-chloro-2-methoxy-4-methylaminobenzamide (YM-09151-2) on operant avoidance responses in rats (author's transl)].

Effects of cis-N-(1-benzyl-2-methylpyrrolidin-3-yl)-5-chloro-2-methoxy-4-methylaminobenzamide (YM-09151-2), a newly synthesized psychotropic agent, on avoidance responses in rats under a Sidman-type avoidance situation (R - 3 = 30 sec, S - S = 5 sec) and discriminated-type avoidance situation (ITI = 25 sec, CS duration = 5 sec) were investigated. The results were compared with the findings obtained in the case of YM-08050, YM-08051 and sulpiride, benzamide derivatives having similar chemical structures as YM-09151-2, and with the effects of chlorpromazine and haloperidol. After administration of YM-09151-2 (0.0025 - 0.01 mg/kg s.c. or 0.2 - 1.6 mg/kg p.o.), we observed a dose-related suppression of the avoidance responses, which attained to the maximum at 2 - 3 hr and persisted for about 24 hr. The average avoidance-suppressing and anti-amphetamine effects during the 2 hr session were in the order of YM-09151-2, YM-08050, haloperidol, YM-08051, chlorpromazine and sulpiride, when these agents were given s.c. Here, the avoidance-suppressing effects of YM-09151-2 were estimated to be 94-137 times as potent as those of chlorpromazine, and 4-37 times as those of haloperidol. After p.o. administration, the suppressing effects on the Sidman-type avoidance response were in the order of YM-08050, YM-08051, haloperidol, YM-09151-2, chlorpromazine and sulpiride, and on the discriminated-type one in the order of YM-08050, YM-09151-2, haloperidol, YM-08051, chlorpromazine and sulpiride. The present results suggest that YM-09151-2 has a more potent avoidance-suppressing effect when it is administered s.c., while the effect is as potent as that of haloperidol when given p.o. The effect appears rapidly and persists for about 24 hr after either s.c. or p.o. administration.