Application A-61603 is an α1A agonist and has been studied to understand the functional roles of α(1)-adrenoceptor subtypes in mouse carotid arteries. A-61603 stimulated phosphoinositide hydrolysis In fibroblast cells transfected with α1a receptors. Biochem/physiol Actions A-61603 is an α1A agonist. In radioligand binding assays, A-61603 was at least 35-fold more potent at α1A receptors than at α1b or α1d sites. In fibroblast cells transfected with α1a receptors, A-61603 more potently stimulated phosphoinositide hydrolysis than norepinephrine, and was antagonized by prazosin. A-61603 is less potent in cells transfected with α1b or α1d receptors. It is a potent agonist at α1A receptors in rat vas deferens (200- to 300-fold more potent than norepinephrine or phenylephrine, respectively) and in isolated canine prostate strips (130- to 165-fold more potent than norepinephrine or phenylephrine, respectively). In contrast, it is only 40-fold more potent than phenylephrine at α1B sites in rat spleen and 35-fold less potent at rat aortic, α1D sites. A-61603 induces a pressor response in conscious rats at doses 50- to 100-fold lower than phenylephrine. |
Application A-61603 is an α1A agonist and has been studied to understand the functional roles of α(1)-adrenoceptor subtypes in mouse carotid arteries. A-61603 stimulated phosphoinositide hydrolysis In fibroblast cells transfected with α1a receptors. Biochem/physiol Actions A-61603 is an α1A agonist. In radioligand binding assays, A-61603 was at least 35-fold more potent at α1A receptors than at α1b or α1d sites. In fibroblast cells transfected with α1a receptors, A-61603 more potently stimulated phosphoinositide hydrolysis than norepinephrine, and was antagonized by prazosin. A-61603 is less potent in cells transfected with α1b or α1d receptors. It is a potent agonist at α1A receptors in rat vas deferens (200- to 300-fold more potent than norepinephrine or phenylephrine, respectively) and in isolated canine prostate strips (130- to 165-fold more potent than norepinephrine or phenylephrine, respectively). In contrast, it is only 40-fold more potent than phenylephrine at α1B sites in rat spleen and 35-fold less potent at rat aortic, α1D sites. A-61603 induces a pressor response in conscious rats at doses 50- to 100-fold lower than phenylephrine. |