[Effects of long-term atenolol treatment on beta-adrenoceptor subtypes in rat heart]

Sheng Li Xue Bao. 1995 Aug;47(4):381-6.
[Article in Chinese]

Abstract

The effects of long-term beta 1-AR selective antagonist atenolol treatment on beta-adrenoceptor subtypes were studied by radioligand binding assay, function determination and cAMP accumulation measerment in rat heart. The reasults showed that during long-term administration of atenolol: (1) The density of total beta-AR was increased by approximately 57%; the positive inotropic response and cAMP formation induced by activation of beta-AR were also enhanced. (2) The 125I-pindol competitive inhibition curve for CGP20712A showed that there were no significant difference in the percentage of beta 1- and beta 2-AR sites between the atenolol treated rats and the control rats; pA2 values for selective beta 1-AR antagonist CGP20712A and pKB values for selective beta 1-AR antagonist ICI 118, 551 were not significantly different in the two groups. The results suggested that beta 1- and beta 2-adrenoceptors were upregulated not only in density but also in positive inotropic effect to the same extent.

Publication types

  • English Abstract
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Atenolol / adverse effects
  • Atenolol / pharmacology*
  • Male
  • Myocardium / metabolism*
  • Rats
  • Rats, Wistar
  • Receptors, Adrenergic, beta / drug effects*
  • Receptors, Adrenergic, beta / metabolism
  • Up-Regulation

Substances

  • Receptors, Adrenergic, beta
  • Atenolol