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: Role of sodium in antigen-induced contraction of tracheal smooth muscle in dogs.
    Author: Yu J, Guia A, Mink S, Kepron W, Cragoe EJ, Sharma S, Bose R.
    Journal: Respir Physiol; 1993 Jan; 91(1):111-24. PubMed ID: 8382833.
    Abstract:
    We examined the role of Na+ influx in the airway response to antigen (ragweed pollen extract) in sensitized dogs, using amiloride analogs to block Na(+)-dependent processes. In in vivo studies, respiratory resistance was measured in amiloride treated and untreated groups. The resistance increased by 9.3 cmH2O.L-1.sec in response to ragweed aerosol in the untreated group, but increased only by 5.2 cmH2O.L-1.sec in the treated group. In in vitro studies, isometric tension was measured in ragweed pollen sensitized tracheal strips. Tissues were treated with amiloride or its derivatives (50 microM) for specifically blocking Na+ channels (phenamil), Na(+)-H+ exchanger [5-(N-methyl-N-guanidinocarbonyl methyl)-amiloride] or Na(+)-Ca2+ exchanger [5-(4-chlorobenzyl)-2',4'-dimethylbenzamil]. In untreated strips, tension increased in response to ragweed by 1.9 +/- 0.5 mN/mg. The increase was reduced by phenamil (95.2 +/- 2.5%; P < 0.01) and amiloride (41.7 +/- 13.1%; P < 0.01), but not by the other two agents. Furthermore, phenamil also inhibited histamine-induced tension response and histamine-induced 22Na+ uptake of the muscle. We conclude that antigen-induced airway response is attenuated by blocking Na+ influx in smooth muscle.
    [Abstract] [Full Text] [Related] [New Search]