Premium
TOLERANCE OF GUINEA‐PIG AIRWAY MUSCLE PREPARATIONS TO RELAXANT AGONISTS INDUCED BY CHRONIC EXPOSURE TO ISO‐PRENALINE in vivo
Author(s) -
BRINK CHARLES
Publication year - 1981
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1981.tb16765.x
Subject(s) - isoprenaline , theophylline , guinea pig , histamine , in vivo , bronchodilator , medicine , endocrinology , desensitization (medicine) , muscle relaxant , chemistry , bronchodilatation , anesthesia , biology , asthma , stimulation , receptor , microbiology and biotechnology
1 The histamine sensitivities of complete tracheal spiral preparations from guinea‐pigs were similar to those of paired half tracheal tissues. 2 Airway muscle preparations from animals chronically treated with isoprenaline showed a significant increase in resting tone and a significant decreased responsiveness to histamine. 3 The paired half tracheal preparations exhibited no significant difference when either their isoprenaline or theophylline sensitivities were compared. 4 Paired half tracheal muscle preparations from chronically treated animals (0.4 μmol, 4.0 μmol, and 40.0 μmol isoprenaline, 3 times daily for 21 days, s.c.) showed a significantly reduced sensitivity to isoprenaline when compared to appropriate controls. 5 Theophylline concentration‐effect curves for the paired half tracheal preparations from chronically treated guinea‐pigs (4.0 μmol and 40.0 μmol isoprenaline) were significantly reduced compared with appropriate controls. 6 Indomethacin treatment reversed the isoprenaline desensitization induced by chronic treatment (0.4 μmol isoprenaline) but was ineffective in animals that received the higher doses of isoprenaline in vivo .