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: Efficiency of beta-adrenoceptor subtype coupling to cardiac adenylyl cyclase in cardiomyopathic and control hamsters.
    Author: Witte K, Schnecko A, Olbrich HG, Lemmer B.
    Journal: Eur J Pharmacol; 1995 Jun 23; 290(1):1-10. PubMed ID: 7664819.
    Abstract:
    Densities of beta-adrenoceptor subtypes and their contributions to stimulation of adenylyl cyclase were studied in heart ventricles from cardiomyopathic (BIO 8262) and control Syrian hamsters (CLAC) at 4 different ages: 30, 100, 200, and 300 days. In BIO ventricles neither total beta-adrenoceptor density nor that of the beta 1-adrenoceptor subtype differed from the controls, whereas the density of beta 2-adrenoceptors was significantly higher in myocardium from 200- and 300-day-old BIO compared to that from age-matched CLAC hamsters. Stimulation of adenylyl cyclase by the non-selective beta-adrenoceptor agonist isoprenaline did not differ between strains, but the beta 1-adrenoceptor mediated component was significantly reduced in cardiomyopathic hamsters of all age groups. In 300-day-old animals beta 1-adrenoceptors accounted for 83% (CLAC) and 68% (BIO) of total beta-adrenoceptor binding sites, whereas only 26% (CLAC) and 6% (BIO) of the isoprenaline effect on cAMP formation were mediated via beta 1-adrenoceptors. Thus, the present study shows a lower coupling efficiency of beta 1-adrenoceptors compared to the beta 2-adrenoceptor subtype in ventricles from healthy Syrian hamsters and a progressive, further reduction in beta 1-adrenergic function in cardiomyopathic animals.
    [Abstract] [Full Text] [Related] [New Search]