A derivative of befunolol, BFE-55, interacts with only the high affinity sites in beta-adrenoceptors |
| |
Authors: | K Koike A Nakagoshi I Takayanagi |
| |
Institution: | Department of Chemical Pharmacology, Toho University School of Pharmaceutical Sciences, Chiba, Japan. |
| |
Abstract: | The effect of BFE-55, a derivative of befunolol (a beta-adrenergic partial agonist) on specific 3H]befunolol binding to a microsomal fraction from the guinea pig taenia caecum was tested. A Scatchard plot of specific 3H]befunolol binding in the absence of BFE-55 was concave, suggesting an existence of high and low affinity sites in beta-adrenoceptors. In contrast, the Scatchard plot of data in the presence of BFE-55 (3 X 10(-7) M) was straight. In the presence of BFE-55, the high affinity sites disappeared and the low affinity site was unaffected. In the absence and presence of BFE-55 there was no difference between the pKD values or Bmax values at the low affinity site. These findings indicate that BFE-55 interacts with only the high affinity sites in beta-adrenoceptors. |
| |
Keywords: | |
|
|