Effect of bupranolol on CGP 12177-induced relaxation and cAMP accumulation in the guinea pig taenia caecum.
1. The effect of bupranolol on CGP 12177-induced relaxation and cAMP accumulation in the guinea pig taenia caecum was examined. 2. The relaxant response to CGP 12177 was unaffected by propranolol (approximately 10(-6) M), whereas that to CGP 12177 was antagonized in a concentration-dependent manner by bupranolol; Schild plot of the data revealed the pA2 value of 5.61. 3. CGP 12177 significantly increased cyclic AMP level in this preparation. Bupranolol (10(-4) M) significantly decreased the cyclic AMP level that was elicited by CGP 12177, whereas propranolol (10(-5) M) produced no effect. 4. These results suggest that bupranolol appears to be an efficient beta3-antagonist in the guinea pig taenia caecum and confirm that the response to CGP 12177 is mediated by beta3-adrenoceptors.
Koike
K
K
Department of Chemical Pharmacology, Toho University School of Pharmaceutical Sciences, Miyama, Funabashi, Chiba, Japan.
Horinouchi
T
T
Takayanagi
I
I
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D002046:Bupranolol / Q000494:pharmacology*; D000242:Cyclic AMP / Q000096:biosynthesis*; D004305:Dose-Response Relationship, Drug; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007422:Intestines / Q000187:drug effects / Q000502:physiology; D008297:Male; D009126:Muscle Relaxation / Q000187:drug effects; D011412:Propanolamines / Q000494:pharmacology*; D011943:Receptors, Adrenergic, beta / Q000187:drug effects*; D022702:Receptors, Adrenergic, beta-3
D000319:Adrenergic beta-Antagonists; D011412:Propanolamines; D011943:Receptors, Adrenergic, beta; D022702:Receptors, Adrenergic, beta-3; D002046:Bupranolol; D000242:Cyclic AMP; C033394:CGP 12177