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: Interaction of selective compounds with muscarinic receptors at dispersed intestinal smooth muscle cells.
    Author: Barocelli E, Chiavarini M, Ballabeni V, Bordi F, Impicciatore M.
    Journal: Br J Pharmacol; 1993 Feb; 108(2):393-7. PubMed ID: 8448589.
    Abstract:
    1. The characterization of muscarinic receptors on single cells of the guinea-pig ileum longitudinal smooth muscle, devoid of neuronal elements, was functionally studied by estimating the affinities of muscarinic antagonists on acetylcholine-induced contractions. 2. Atropine (5 x 10(-11) to 5 x 10(-6) M), 4-diphenylacetoxy-N-methyl-piperidine methiodide (4-DAMP, 5 x 10(-8) to 5 x 10(-6) M), cyclohexyl(4-fluoro-phenyl) (3-piperidinopropyl) silanol (pFHHSiD, 5 x 10(-7) to 5 x 10(-5) M) as well as pirenzepine (5 x 10(-7) to 5 x 10(-5) M) competitively antagonized the acetylcholine-dependent contractions with different affinities (atropine > 4-DAMP > pFHHSiD > pirenzepine). 3. Methoctramine (5 x 10(-7) to 5 x 10(-5) M), and AF-DX 116 (5 x 10(-6) and 5 x 10(-5) M) also showed antagonist properties but these deviated from simple competition. These compounds, which discriminate between M2 and M3 receptors, showed a potency lower than that of pirenzepine, the rank order of potencies being pirenzepine > methoctramine > AF-DX 116. When concentrations of AF-DX 116, methoctramine and pirenzepine were increased an unspecific contractile effect occurred. 4. McN-A-343, a partial agonist on intact guinea-pig longitudinal smooth muscle strips, on this preparation induced a weak contraction (about 7% in comparison to control) that was not reversed by antimuscarinic agents. 5. These data indicate that M3 rather than M2 receptor sites are present on this tissue.
    [Abstract] [Full Text] [Related] [New Search]