title: Characterization of the alpha 1-adrenoceptors of rat white fat cells.
abstract: Activation of alpha 1-adrenoceptors stimulates the labeling of phosphatidylinositol in rat fat cells. The potency order of agonists was: epinephrine greater than norepinephrine greater than methoxamine; phenylephrine was a partial agonist for this effect. The action of norepinephrine was blocked by alpha-adrenergic antagonists in the following order of potency: prazosin greater than phentolamine greater than phenoxybenzamine greater than yohimbine. Trypsinization of fat cells nearly abolished the effect of norepinephrine indicating that alpha 1-adrenoceptor activation occurs at the outer surface of the plasma membrane.
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism*; D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000818:Animals; D066298:In Vitro Techniques; D009638:Norepinephrine / Q000037:antagonists & inhibitors; D010716:Phosphatidylinositols / Q000378:metabolism; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011941:Receptors, Adrenergic / Q000378:metabolism*; D011942:Receptors, Adrenergic, alpha / Q000378:metabolism*
chemical_list: D000316:Adrenergic alpha-Agonists; D000317:Adrenergic alpha-Antagonists; D010716:Phosphatidylinositols; D011941:Receptors, Adrenergic; D011942:Receptors, Adrenergic, alpha; D011433:Propranolol; D009638:Norepinephrine