Results of a previous study showed that ethanol inhibition of hippocam
pal long-term potentiation (LTP) induction was mediated by angiotensin
II (AII) and the AT(1) subtype receptor because it was blocked by los
artan, a specific AT(1) antagonist. Because LTP is an important hippoc
ampal function involved in the memory process and other behaviors, it
is possible that losartan might block some of the directly observable
ethanol-induced changes in rat behavior. Results demonstrate that losa
rtan can effectively block some of the intoxicating effects of low dos
es of ethanol, 2 g/kg PO or IP. However, even a high dose of losartan
20 mg/kg IP, did not reduce significantly any of the intoxicating effe
cts of the higher dose of 4 g/kg administered by gavage. Higher doses
of ethanol might be more difficult to block because of a direct effect
on the post synaptic membrane.