Abstract
Stereospecific binding sites for (-) [3H]-alprenolol, a beta-adrenergic antagonist, have been identified in guinea-pig myocardial broken cell preparations. The concentration of the sites was 0.3 pmoles per mg of protein and the dissociation constant (at 37 degrees C) 10(-8) M. A close correlation between the ability of various beta-adrenergic antagonists to compete with tracer alprenolol binding and to block the response of isoprenaline-stimulated myocardial adenylate cyclase has been found. Low affinity sites for the labelled beta-adrenergic antagonist in contrast to stereospecific sites are heat stable and do not discriminate between the (-) and the (+) forms of the beta-adrenergic antagonists. Adenylate cyclase in guinea-pig myocardial tissue is poorly stimulated by isoprenaline or 5'-guanylylimidodiphosphate. This is attributed to a high basal activity which could be lowered by a preincubation at 37 degrees C.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
