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: The influence of extracellular calcium on muscarinic receptors in vascular smooth muscle.
    Author: Carrier GO, Ahlquist RP.
    Journal: Arch Int Pharmacodyn Ther; 1976 Oct; 223(2):223-30. PubMed ID: 999407.
    Abstract:
    The present study was designed to investigate the influence of extracellular calcium (Ca++) on the affinity of cholinergic agonists and antagonists for muscarinic receptors in isolated rabbit aortic strips. Dose-response curves which demonstrate the effect of acetylcholine on the force of contraction in the presence of various Ca++ concentrations were made. The affinity constant was calculated and the intrinsic activity was determined at each of the different Ca++ concentrations used. In addition, the relationship between extracellular Ca++ and the pA2 value for atropine was determined. No apparent relationship between the affinity of acetylcholine for the cholinergic receptors and Ca++ concentration in vascular muscle was demonstrated. However, the intrinsic activity was altered when the extracellular Ca++ was varied. In addition, atropine was effective to the same degree both in the presence and complete absence of Ca++. These results are discussed in relation to the dependency of acetylcholine on extracellular Ca++ to induce contractile responses after receptor occupancy in vascular muscle.
    [Abstract] [Full Text] [Related] [New Search]