Results of previous research demonstrate that angiotensin II (Ang II)
inhibits long-term potentiation (LTP) in medial perforant path-dentate
gyrus granule cells and that the inhibition is mediated by the AT(1)
receptor because it can be blocked by losartan, a specific AT(1) recep
tor antagonist. Ang II impairment of retention and ethanol inhibition
of LTP can both be blocked by pretreatment with losartan. Because losa
rtan pretreatment also prevents ethanol intoxication measured in terms
of the aerial righting reflex, the purpose of the present study was t
o assess the effects of 2.0 g/kg ethanol administered by gavage on per
formance in an eight-arm radial maze, and then to determine the effect
iveness of losartan in reducing the impairment of the learning and mem
ory process. Results confirmed the general hypothesis that ethanol-ind
uced cognitive deficits are mediated by Ang II and the AT(1) receptor
and that the impairment can be reduced by pretreatment with losartan.
(C) 1997 Elsevier Science Inc.