NIOSHTIC-2 Publications Search

HOCl causes airway substance P hyperresponsiveness and neutral endopeptidase hypoactivity.

Murlas CG; Murphy TP; Lang Z

Am J Physiol, Lung Cell Mol Physiol 1990 Jun; 258(6):L361-L368

https://doi.org/10.1152/ajplung.1990.258.6.L361

00232156

Guinea-pig tracheal tissue was exposed to hypochlorous-acid (7790923) (HOCl) or hydrogen-peroxide (7722841) (H2O2) in an effort to determine whether there would be any effect on the responsiveness of airway muscle to acetylcholine (ACh), potassium-chloride (KCl), or substrate-P in the presence or absence of phosphoramidon. Tracheas were isolated from male Hartley-guinea-pigs, and used for airway contraction studies. Tissues were exposed to HOCl or H2O2 by perfusion through the airway lumen. A hyperresponsiveness to substance-P was noted in smooth muscle of mucosa intact guinea-pig airways which had been perfused with HOCl but not H2O2. No hyperreactivity was noted in response to ACh or KCl. Phosphoramidon pretreated, HOCl perfused rings behaved the same as Krebs solution exposed controls. An association between hyperresponsiveness and decreased neutral endopeptidase (NEP) activity was noted. In studying the catabolism of substance-P, it was noted that HOCl or phosphoramidon exposure decreased substance-P disappearance from the perfusates. The authors suggest that smooth muscle hyperresponsiveness to substance-P caused by the perfusion of airways with HOCl occurs through HOCl inactivation of mucosal NEP.

NIOSH Publication; NIOSH Grant; Pulmonary system disorders; Enzyme activity; Laboratory animals; Respiratory irritants; Oxidizers; Lung irritants; Mucous membranes; Author Keywords: airway hyperreactivity; asthma; bronchoconstriction; bronchial reactivity; enkephalinase; guinea pig; hypohalous acids; metalloendopeptidase; muscarinic receptors; oxidant injury; tachykinins; trachealis muscle

Christopher G. Murlas, Internal Medicine Univ of Tennessee, Memphis 956 Court Avenue Memphis, TN 38163

APLPE7

7790-92-3; 7722-84-1

19900601

Journal Article

127961

Grant

1990

Grant-Number-K01-OH-00060

6

1040-0605

Pulmonary-system-disorders

American Journal of Physiology: Lung Cellular and Molecular Physiology

OH

University of Cincinnati, Cincinnati, Ohio