Regulation of adrenergic receptor function by phosphorylation. I. Agonist-promoted desensitization and phosphorylation of α1-adrenergic receptors coupled to inositol phospholipid metabolism in DDT1 MF-2 smooth muscle cells
Continuous exposure of DDT1 MF-2 smooth muscle cells to 10-100 μM norepinephrine results in a dramatic attenuation of the ability of norepinephrine to stimulate inositol phospholipid hydrolysis via α1-adrenergic receptors (α1-AR). In addition to the functional desensitization, norepinephrine exposure also reduces the number of accessible cell surface α1-AR as assayed by [3H]prazosin binding at 4°