Faculty Collaboration Database

Differential bronchodilatory effects of terbutaline, diltiazem, and aminophylline in canine intraparenchymal airways. Crit Care Med 1999 Aug;27(8):1551-6

Date

09/02/1999

Pubmed ID

10470763

DOI

10.1097/00003246-199908000-00024

Scopus ID

2-s2.0-0032866503 (requires institutional sign-in at Scopus site)   2 Citations

Abstract

OBJECTIVES: Intraparenchymal airways are involved in air flow regulation. Relaxation of intraparenchymal airways to volatile anesthetics varied by topographic location. This study was conducted to determine whether other bronchodilators (terbutaline, diltiazem, and aminophylline) relax bronchiolus to a greater degree than bronchus, as seen with volatile anesthetics.

DESIGN: In vitro, controlled, randomized study.

SETTING: Animal research laboratory.

SUBJECTS: Adult dogs (n = 9).

INTERVENTIONS: Proximal (outer diameter, 4-6 mm) and distal (outer diameter, 0.8-1.5 mm) airway rings of dogs were contracted in tissue baths with the effective concentration of acetylcholine that produces half the maximum response. Airway relaxant dose-response curves were constructed to measure isometric tension after administration of terbutaline (concentration range, 10(-8) to 10(-4) M), diltiazem (concentration range, 3 x 10(-7) to 1 x 10(-4) M), and aminophylline (concentration range, 10(-7) to 10(-4) M).

MEASUREMENTS AND MAIN RESULTS: All three bronchodilators caused relaxation of the proximal and distal airways. At the maximum dose, diltiazem (maximum relaxation, 95%+/-2% [proximal], 94%+/-6% [distal]; p > .05) was the most efficacious, followed by terbutaline (maximum relaxation, 72%+/-13% [proximal], 55%+/-9% [distal]; p < .05) and aminophylline (maximum relaxation, 32%+/-10% [proximal], 35%+/-18% [distal]; p > .05. At the concentrations tested, they were equally efficacious. No significant differences in relaxation between proximal and distal airways were noted with diltiazem or aminophylline in the entire dose range. However, terbutaline relaxed the distal airway more than the proximal airway in the entire dose range.

CONCLUSIONS: The results demonstrate that only terbutaline showed a differential airway relaxant effect between proximal and distal airways, as seen with volatile anesthetics.

Author List

Akhtar S, Mazzeo AJ, Cheng EY, Bosnjak Z, Kampine JP

MESH terms used to index this publication - Major topics in bold

Aminophylline
Analysis of Variance
Anesthetics, Inhalation
Animals
Bronchi
Bronchodilator Agents
Diltiazem
Dogs
Dose-Response Relationship, Drug
Drug Evaluation, Preclinical
Female
In Vitro Techniques
Linear Models
Male
Muscle, Smooth
Random Allocation
Terbutaline