Response of bronchial smooth muscle to mast cell degranulation in situ

J Appl Physiol Respir Environ Exerc Physiol. 1983 Dec;55(6):1803-10. doi: 10.1152/jappl.1983.55.6.1803.

Abstract

We studied the response of bronchial smooth muscle to mast cell degranulation with Ascaris suum antigen (AA) and compound 48/80 (48/80) in 26 mongrel dogs in situ. Bronchial smooth muscle response was measured isometrically in situ from a segment of the right middle lobe bronchus; tracheal response was monitored isometrically as a control. After intra-arterial (ia) injection of AA into the bronchial circulation, bronchial contraction preceded tracheal contraction by 19.2 +/- 4.6 s (P less than 0.002). Bronchial contraction to AA (21.7 +/- 3.4 g) was substantially greater than to 48/80 (10.5 +/- 1.8 g, P less than 0.05) corresponding to differences in maximal systemic histamine concentrations (146 +/- 24.1 vs. 1000 +/- 236 ng/ml, P less than 0.01). In 5 dogs, the effect of leukotriene D4 (LTD4) and FPL 55712 was studied. Injection of 10(-8) mol ia LTD4 caused no bronchial contraction. In four dogs, 10(-7) mol FPL 55712 caused no bronchial relaxation after initial precontraction during immune degranulation with AA; intravenous chlorpheniramine (5 mg/kg) caused 69.7 +/- 9.4% relaxation. We demonstrate a model that permits selective immune degranulation of a single major resistance bronchus in situ. We conclude that AA-induced degranulation in dogs caused bronchial contraction predominantly by secretion of preformed mediator.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antigens / immunology
  • Ascaris / immunology
  • Biomechanical Phenomena
  • Bronchi / drug effects
  • Bronchi / immunology
  • Bronchi / physiology*
  • Dogs
  • Female
  • Histamine / blood
  • Male
  • Mast Cells / immunology
  • Mast Cells / physiology*
  • Muscle, Smooth / drug effects
  • Muscle, Smooth / immunology
  • Muscle, Smooth / physiology*
  • p-Methoxy-N-methylphenethylamine / pharmacology

Substances

  • Antigens
  • p-Methoxy-N-methylphenethylamine
  • Histamine