These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Beta-adrenoceptor blocking and electrophysiological effects of bufetolol in the guinea pig atria.
    Author: Inui J, Imamura H.
    Journal: Eur J Pharmacol; 1977 Feb 07; 41(3):251-60. PubMed ID: 14011.
    Abstract:
    The potency of blockade of bufetolol, a beta-adrenoceptor blocking drug, and effects of bufetolol on the action potential, contractile force and various electrophysiological properties of the atrium were investigated in comparison with propranolol and quinidine. Bufetolol had a pA2 of 8.65 against the positive chronotropic action of isoproternol on the guinea pig sinus node. Bufetolol, 10(-7) g/ml, did not affect the action potential of the atrial muscle, while the drug, 3 X 10(-5) g/ml, significantly decreased the overshoot potential, the amplitude and the maximum rate of rise of the action potential and prolonged the times for 50% and 90% repolarization. The contractile force was reduced by bufetol, 3 X 10(-5) g/ml. The maximum responsive frequency to the driving stimulus was decreased by bufetol, 3 X 10(-5) g/ml. The excitability of the muscle membrane was suppressed by bufetolo, 3 X 10(-5) g/ml, as indicated by changes in membrane responsiveness, membrane reactivation and strength-duration curve. Propranolol, 10(-5) g/ml and quinidine, 10(-5) g/ml showed similar effects on excitability. The authors suggest that these effects of bufetolol are responsible for its antidyshythmic effects.
    [Abstract] [Full Text] [Related] [New Search]