EFFECTS OF ANGIOTENSIN-II ON BRAIN MONOAMINES IN NONHYPOXIC AND HYPOXIC MICE

The effects of angiotensin II (ATII) administered intracerebroventricu larly (ICV, acute) and subcutaneously (SC, acute and chronic) on acute hypoxia (asphyctic and hemic), and on the forebrain concentrations of monoamines dopamine (DA), norepinephrine (NE), and serotonin (5-HT) i n male mice were studied. ATII in both routes of administration exerte d a decrease of the latency to hypoxia-induced convulsions. ATII sligh tly reduced the brain levels of DA and NE, and did not change those of 5-HT in hypoxic mice. ATII significantly reduced DA and 5-HT concentr ations in nonhypoxic (normoxic) mice. Taken together, the results sugg est that ATII-induced increase of susceptibility to hypoxia is accompa nied by slight alterations in the brain monoamine metabolism.