Adrenergic antagonist binding

Neubig, R. R., Gantzos, R. D., and Thomsen, W. J. (1988). Mechanism of agonist and antagonist binding to alpha-2 adrenergic-receptors—evidence for a precoupled receptor guanine-nucleotide protein complex. Biochemistry 27, 2374-2384. 

Dobutamine is structurally similar to dopamine but does not bind to dopamine receptors and is not associated with norepinephrine release from neurons. The drug exists as a racemic mixture, both isomers possesses p adrenergic effects, with the (+) enantiomer (eutomer) being 10 times more potent than the (-) enantiomer (distomer). Furthermore, the eutomer is a potent a adrenergic antagonist while the distomer is a potent... 

Bylund DB, Ray-Prenger C, Murphy TJ. a2A and a2B adrenergic receptor subtypes antagonist binding in tissues and cell lines containing only one subtype. J Pharmacol Exp Ther 1988 245 600-607. 

Alpha blockers Alpha adrenergic antagonists compete with endogenous catecholamines for binding at and CC receptors. Because norepinephrine and epinephrine cannot bind to a receptor that is occupied by an antagonist, the actions of catecholamines at... 

V 1 1 IV. 6 hr half-life, partially metabolized in liver, low plasma protein binding. Hypersensitivity to amrinone. Amrinone increases diuresis in patients on diuretics. Digitalis inotropy and risk of toxicity increased (amrinone causes hypokalemia). Excessive hypotension with disopyramide. If cellular supplies of cAMP are depleted, amrinone will not be effective. Capable of increasing myocardial contraction even in the presence of p-adrenergic antagonists. 

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