Inhibition of polyphosphoinositide turnover in rat cerebral cortex by clonidine

摘要: Abstract In the rat brain, a number of receptors are linked to phospholipase C which catalyzes hydrolysis membrane inositol phospholipids; stimulation α 1 -adrenergic receptors, for example, increases polyphos-phoinositide turnover, but 2 -receptors does not. The phospholipids in cortical slices was investigated using direct assay involving prelabeling these lipids with 3 H-inositol and then measuring formation phosphates presence lithium ions. As expected, clonidine, an -agonist, did not stimulate phosphates; however, clonidine antagonized ability noradrenaline phosphate formation. This effect blocked by antagonists , 5HT H or muscarinic receptors. Clonidine affect carbachol-stimulated