Prazosin protects vascular alpha-adrenoceptors against irreversible blockade by phenoxybenzamine.
The interaction of prazosin with the vascular alpha-adrenoceptor was studied in isolated vessel preparations by means of receptor protection experiments. Prazosin was compared to phentolamine. Prazosin, like phentolamine protected the receptor against irreversible blockade by phenoxybenzamine. It is concluded that prazosin acts by a direct occupancy block of the vascular alpha-receptor.
D000818:Animals; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D010643:Phenoxybenzamine / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D010646:Phentolamine / Q000494:pharmacology; D011189:Potassium Chloride / Q000494:pharmacology; D011224:Prazosin / Q000494:pharmacology*; D011799:Quinazolines / Q000494:pharmacology*; D011817:Rabbits; D051381:Rats; D011941:Receptors, Adrenergic / Q000187:drug effects*; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects*
D011799:Quinazolines; D011941:Receptors, Adrenergic; D011942:Receptors, Adrenergic, alpha; D010643:Phenoxybenzamine; D011189:Potassium Chloride; D011224:Prazosin; D010646:Phentolamine