Angiotensin II-norepinephrine relationship in the central nervous system.
The effects of angiotensin II (AII) and bilateral nephrectomy on [3H] norepinephrine (NE) uptake in hypothalamus and medulla oblongata were studied in male rats. The endogenous NE content in hypothalamus increased 4, 24 and 48 h after nephrectomy with a simultaneous decreasing of plasma renin activity. Intraventricularly infused [3H] NE uptake increased in hypothalamus and medulla oblongata of nephrectomized animals in cytoplasmatic compartment as in granular stores, while it decreased in hypothalamus of AII-infused animals. [3H] NE metabolites radioactivity decreased in nephrectomized animals if they are compared with AII-infused ones. These changes were independent of systolic arterial pressure that was not modified in none of the groups. The study of the ratio granular/cytoplasmatic [3H] NE and metabolites radioactivity shows that AII probably acts on cellular membrane uptake of NE. The modification of metabolites/NE ratio in both stores would be due to AII action on MAO activity. The effects of AII and nephrectomy on [3H] NE uptake can explain the inverse relationship between circulating AII levels and NE content in the central nervous system (CNS).
D000804:Angiotensin II / Q000378:metabolism*; D000818:Animals; D001794:Blood Pressure; D001921:Brain / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D007031:Hypothalamus / Q000378:metabolism; D008297:Male; D008526:Medulla Oblongata / Q000378:metabolism; D009392:Nephrectomy; D009638:Norepinephrine / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012083:Renin / Q000097:blood
D000804:Angiotensin II; D012083:Renin; D009638:Norepinephrine