Characterization of the beta-adrenoceptors in coronary vasculature of the dog heart.
In the present study an attempt has been made to characterize the beta-adrenoceptors of coronary vasculature in dog. Blockade of beta 1-adrenoceptors with ICI 50172 or beta 2-adrenoceptors with RB2 showed only partial antagonism of isoprenaline-induced decrease in coronary resistance. However, combined treatment with ICI 50172 and RB2 completely blocked the isoprenaline-induced fall in coronary resistance. Essentially similar results were observed in controlled heart rate experiments where the drugs were administered locally into the coronary circulation. These results demonstrate the involvement of both beta 1 and beta 2 adrenoceptors in isoprenaline-induced coronary vasodilation.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003331:Coronary Vessels / Q000032:analysis* / Q000187:drug effects; D004285:Dogs; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D011217:Practolol / Q000494:pharmacology; D011941:Receptors, Adrenergic / Q000032:analysis*; D011943:Receptors, Adrenergic, beta / Q000032:analysis* / Q000187:drug effects; D014655:Vascular Resistance / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects
D011941:Receptors, Adrenergic; D011943:Receptors, Adrenergic, beta; D007545:Isoproterenol; D011217:Practolol