%0 Journal Article %T Morphine has latent deleterious effects on the ventilatory responses to a hypoxic challenge* %A Walter J. May %A Ryan B. Gruber %A Joseph F. Discala %A Veljko Puskovic %A Fraser Henderson Jr. %A Lisa A. Palmer %A Stephen J. Lewis %J Open Journal of Molecular and Integrative Physiology %P 166-180 %@ 2162-2167 %D 2013 %I Scientific Research Publishing %R 10.4236/ojmip.2013.34022 %X
The aim of this study was to determine whether morphine depresses the ventilatory responses elicited by a hypoxic challenge (10% O2, 90% N2) in conscious rats at a time when the effects of morphine on arterial blood gas (ABG) chemistry, Alveolar-arterial (A-a) gradient and minute ventilation (Vm) had completely subsided. In vehicle-treated rats, each episode of hypoxia stimulated ventilatory function and the responses generally subsided during each normoxic period. Morphine (5 mg/kg, i.v.) induced an array of depressant effects on ABG chemistry, A-a gradient and Vm (via decreases in tidal volume). Despite resolution of these morphine-induced effects, the first episode of hypoxia elicited substantially smaller increases in Vm than in vehicle-treated rats, due mainly to smaller increases in frequency of breathing. The pattern of ventilatory responses during subsequent episodes of hypoxia and normoxia changed substantially in morphine-treated rats. It is evident that morphine haslatent deleterious effects on ventilatory responses elicited by hypoxic challenge.
%K Morphine %K Hypoxia %K Minute Ventilation %K Arterial Blood Gas Chemistry %K Conscious Rats %U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=39563