Effects of beta-phenylethylamine on polyphosphoinositide turnover in rat cerebral cortex.
The effects of the trace amine, beta-phenylethylamine, on the hydrolysis of inositol phospholipids in rat cerebral cortical slices was studied using a direct assay involving prelabeling with [3H]inositol and then examining the production of [3H]inositol phosphates in the presence of lithium. Phenylethylamine exhibited two different effects. Millimolar concentrations of phenylethylamine stimulated the production of [3H]inositol phosphates to about 200% of control, while much smaller concentrations (micromolar) inhibited noradrenaline(NE)-stimulated [3H]inositol phosphate formation dose-dependently. The alpha 1-antagonist, prazosin, inhibited the increases in [3H]polyphosphoinositide turnover stimulated by phenylethylamine and by NE, though it inhibited phenylethylamine to a lesser extent than NE. It appears, therefore, that phenylethylamine affects [3H]inositol phosphate formation by acting as a partial alpha 1-agonist.
Dyck
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Department of Psychiatry, University of Saskatchewan, Saskatoon, Canada.
Boulton
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AA
D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology; D010627:Phenethylamines / Q000494:pharmacology*; D010716:Phosphatidylinositols / Q000378:metabolism*; D011224:Prazosin / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects / Q000378:metabolism*
D010627:Phenethylamines; D010716:Phosphatidylinositols; D011942:Receptors, Adrenergic, alpha; C029261:phenethylamine; D009638:Norepinephrine; D011224:Prazosin