Effect of maturation on topographic distribution of bronchoconstrictor responses in large diameter airways of young swine.

Published

Journal Article

We studied the effect of maturation on the topographic distribution of airway constriction in Generations 0 (trachea) through 6 in fourteen 2-wk-old swine (2ws) and sixteen 10-wk-old swine (10ws) in vivo and in excised airways from seven 2ws and seven 10ws in vitro. Animals were anesthetized with chloralose-urethane and received beta-adrenergic blockade and vagotomy prior to generation of random-order, dose-response curves with i.v. methacholine (MCh) and histamine (His) or serotonin (5HT) given intravenously. Lung resistance (RL) was measured, and airway diameter was assessed by tantalum bronchograms obtained at functional residual capacity for each dose of agonist. Baseline RL was substantially greater in 2ws (48 to 62 cm H2O/L/s) than in 10ws (9 to 11 cm H2O/L/s; p less than 0.001 for all groups). Intravenous infusion of 10(-6) mol/kg MCh caused a 416 +/- 110% increase in RL in 2 ws and a 314 +/- 32% increase in RL in 10 ws (p = NS); airway diameter (Daw) decreased by 10 +/- 1% (Generation 2) to 27 +/- 4% (Generation 6) in 2ws and from 8 +/- 2 (Generation 2) to 17 +/- 4% in 10ws. Intravenous infusion of 10(-6) mol/kg His caused a 513 +/- 85% increase in RL in 2ws and a 276 +/- 17% increase in RL in 10 ws (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Full Text

Duke Authors

Cited Authors

  • Murphy, TM; Roy, L; Phillips, IJ; Mitchell, RW; Kelly, EA; Munoz, NM; Leff, AR

Published Date

  • January 1, 1991

Published In

Volume / Issue

  • 143 / 1

Start / End Page

  • 126 - 131

PubMed ID

  • 1670916

Pubmed Central ID

  • 1670916

International Standard Serial Number (ISSN)

  • 0003-0805

Digital Object Identifier (DOI)

  • 10.1164/ajrccm/143.1.126

Language

  • eng

Conference Location

  • United States