Effects of a new TRH analogue, YM-14673, on disturbance of passive avoidance learning in senescence-accelerated mice.
Effects of a new TRH analogue, YM-14673 (N alpha-[[(S)-4-oxo-2-azetidinyl]carbonyl]-L-histidyl-L-prolinamide dihydrate), on disturbance of passive avoidance behavior were observed in senescence-accelerated mice (SAM). Latency of step-through in SAM-P/8/Ta (SAM-P/8, senescence-prone substrain) was significantly shorter than that in SAM-R/1/Ta (SAM-R/1, senescence-resistant substrain). Successive oral administration of YM-14673 (1 and 10 mg/kg) and TRH (10 mg/kg) for 3 weeks prolonged the shortened latency of step-through. These results suggest that YM-14673 is more potent than TRH in antiamnesic activities.
Yamamoto
M
M
Department of Pharmacology, Central Research Laboratories Yamanouchi Pharmaceutical Co. Ltd., Tokyo, Japan.
Iwai
A
A
Ozawa
Y
Y
D000375:Aging / Q000502:physiology*; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects* / Q000502:physiology; D001384:Azetidines / Q000494:pharmacology*; D001385:Azetines / Q000494:pharmacology*; D004151:Dipeptides / Q000494:pharmacology*; D051379:Mice; D013973:Thyrotropin-Releasing Hormone / Q000031:analogs & derivatives / Q000502:physiology*
D001384:Azetidines; D001385:Azetines; D004151:Dipeptides; D013973:Thyrotropin-Releasing Hormone; C054995:azetirelin