PT  - JOURNAL ARTICLE
AU  - Ferenc Petak
AU  - Gergely Fodor
AU  - Adam Balogh
AU  - Laszlo Fazekas
AU  - David Telegdi
AU  - Orsolya Ivánkovitsné Kiss
AU  - Barna Babik
TI  - Effects of dopamine on the elevated airway tone by histamine and methacholine in rabbits
DP  - 2014 Sep 01
TA  - European Respiratory Journal
PG  - P3543
VI  - 44
IP  - Suppl 58
4099  - http://erj.ersjournals.com/content/44/Suppl_58/P3543.short
4100  - http://erj.ersjournals.com/content/44/Suppl_58/P3543.full
SO  - Eur Respir J2014 Sep 01; 44
AB  - The beneficial effects of dopamine (DA) on the cardiovascular system have been well established; however the potential mechanisms of how it alters the airway tone have not been clarified. Therefore, we aimed at characterizing the changes in the airway function following DA administrations, when the bronchial tone is elevated via stimulating the histaminic or the cholinergic pathway.The input impedance of the respiratory system (Zrs) was measured in anaesthetized mechanically ventilated rabbits (n=10) under the control conditions, and during iv infusions of methacholine and histamine, in random sequence. After a stable level of bronchoconstriction has been reached, iv DA (5 and 15 µg/kg/min) was administered. Airway resistance (Raw) was determined from the Zrs spectra under each experimental condition by model fitting. The thermodilution method was used to measure cardiac index (CI).The beneficial cardiovascular effect of DA was reflected in the increases in CI (14±10[SE]%, p=0.034). The bronchoconstriction induced by methacholine (55.6±8.6% increase in Raw) and histamine (58.4±8.4%) were significantly inhibited by DA (-9.4±3.2% and -11.0±2.9%; p<0.05 for both) independent of its dose, without observing a difference between the mode of stimuli.These findings indicate that the mechanism of how DA relaxes the elevated airway smooth muscle tone is independent of the mode of constrictor stimuli. This generalized beneficial profile of DA suggests the ability of this drug to provide an effective treatment of respiratory adverse events involving bronchoconstriction, besides its positive inotropic effects on the myocardial contractility.Grant support: OTKA K81169, TÁMOP 4.2.2.A-11/1/KONV-2012-0052.