Abstract
We characterized the complete time course of histamine-induced bronchoconstriction and its modulation via the release of endogenous catecholamines and by its actions on H2-receptors in anesthetized, tracheostomized, paralyzed, and artificially ventilated mongrel dogs. Respiratory resistance (R) and elastance (E) were estimated continuously with a recursive least squares estimator. Three protocols were followed in which multiple histamine bolus injections were given 1 h apart. We found that the time courses of E and R had consistent patterns (transient peak that returned to baseline within 1000 sec) even in cases of low mean arterial pressure (MAP). Indomethacin pre-treatments prevented tachyphylaxis to repeated i.v. challenges. β-blockade produced a mild increase in baseline and a potentiation of the histamine-induced response in E and these effects were not altered with further α-or H2-blockade. Blockade of α-receptors increased the time to recovery in both E and MAP presumably by decreasing blood flow. Finally, we suggest that preventing the H2-receptor induced increase in bronchial blood flow may have increased the time to maximal E without affecting the recovery time.
Original language | English |
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Pages (from-to) | 127-138 |
Number of pages | 12 |
Journal | Respiration Physiology |
Volume | 99 |
Issue number | 1 |
DOIs | |
Publication status | Published - Jan 1995 |
Externally published | Yes |
Bibliographical note
Funding Information:The authors are thankful to Mr. W. Lubenskyi from the Jewish General Hospital, Lady Davis Institute, 3755 St-Catherine, Montreal, Quebec, Canada, H3T 1E2, for performingt he HPLC cat-echolaminea ssays.T he authors are also indebtedt o Ciba-Geigy Canada Ltd., 6860 Century Avenue, MississaugaO, ntario,L5N 2W5, for kindly providing the phentolaminen eeded to accomplish this study. Finally, the authors want to thank Rosetta Pantano and Deanna Collin for their technicalh elp in getting blood samples in the awake dogs. This work was supportedb y the Medical ResearchC oun-cil of Canada, the J.T. Costello Memorial Research Fund, and the RespiratoryH ealthNetwork of Centers of ExcellenceA. .-M. Lauzon is supportedb y the ResearchI nstituteof the Montreal Chest Hospital, Montreal, G. Dechman is supportedb y the Physiotherapy Society of the Canadian Lung Association, J.G. Martin is a scientisto f the Medical Research Council of Canada, and J.H.T. Bates is a Chercheur-boursier of the Fonds de la Recherchee n Sant6 du Quebec.
ASJC Scopus Subject Areas
- Physiology
- Pulmonary and Respiratory Medicine