Effects of angiotensin II on [3H]noradrenaline release and phosphatidylinositol hydrolysis in the parietal cortex and locus coeruleus of the rat.
Angiotensin II (ANGII) (3-100 nM) facilitated the potassium-evoked (22.5 mM) release of [3H]-noradrenaline ([3H]NA) from slices of parietal cortex in a concentration-dependent manner, but did not significantly alter the release of [3H]NA evoked in a similar manner from locus coeruleus slices. The facilitatory action of ANGII was blocked by saralasin (0.1-3 microM). Neither nimodipine (10-30 microM) nor phenylmethylsulphonyl fluoride (1 mM) altered either [3H]NA release or the facilitatory action of ANGII in the parietal cortex. Carbachol (0.01-3 mM) and raised potassium (22.5 mM), but not ANGII (3-100 nM), stimulated the production of inositol phosphates in parietal cortex slices. The potassium-evoked increase in inositol phosphate production was unaffected by ANGII (3-100 nM). In the locus coeruleus, ANGII (3-100 nM) did not stimulate inositol phosphate production. The mechanism underlying the ANGII facilitation of [3H]NA release from the parietal cortex does not appear to involve either nimodipine-sensitive calcium channels, or, as far as we have been able to determine, the release of calcium from intracellular stores following the breakdown of phosphoinositides.
Huang
Y
Y
Department of Pharmacology, University of Cambridge, England.
Rogers
J
J
Henderson
G
G
D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D004347:Drug Interactions; D006868:Hydrolysis; D008125:Locus Coeruleus / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D009553:Nimodipine / Q000494:pharmacology; D009638:Norepinephrine / Q000378:metabolism*; D010296:Parietal Lobe / Q000187:drug effects / Q000378:metabolism*; D010716:Phosphatidylinositols / Q000378:metabolism*; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D012504:Saralasin / Q000494:pharmacology; D015016:Yohimbine / Q000494:pharmacology
D010716:Phosphatidylinositols; D000804:Angiotensin II; D015016:Yohimbine; D009553:Nimodipine; D002217:Carbachol; D012504:Saralasin; D011188:Potassium; D009638:Norepinephrine