Interaction of a beta-adrenergic partial agonist with its receptor in guinea-pig taenia caecum.
Beta-adrenoceptor mechanisms in guinea-pig taenia caecum were studied by means of a receptor-binding technique. Hill plots of test drugs obtained from inhibition curves were linear with slopes which were equal to 1.00. pKi-values of isoprenaline and desisopropylprocaterol were in agreement with those pD2-values. pKi-value of carteolol was in agreement with its pA2-value. The beta-adrenoceptor is suggested to have two different sites; one can interact with the agonist and partial agonist and the other can interact with the antagonist and partial agonist.
D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000818:Animals; D002354:Carteolol / Q000494:pharmacology; D002432:Cecum / Q000378:metabolism; D004082:Dihydroalprenolol / Q000494:pharmacology; D004983:Ethanolamines / Q000494:pharmacology; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D008861:Microsomes / Q000378:metabolism; D009130:Muscle, Smooth / Q000378:metabolism*; D011869:Radioligand Assay; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*
D000318:Adrenergic beta-Agonists; D004983:Ethanolamines; D011943:Receptors, Adrenergic, beta; D004082:Dihydroalprenolol; C038367:desisopropylprocaterol; D002354:Carteolol; D007545:Isoproterenol