Biomaterial Database

Effect of alpha-adrenoreceptor stimulation on the diaphragmatic oxygen delivery-consumption relationship. 1996

M E Ward, and S N Hussain

Division of Critical Care Medicine, Royal Victoria Hospital, McGill University, Montreal, Quebec, Canada.

OBJECTIVE In the vascularly isolated canine hemidiaphragm, we tested the hypothesis that alpha-adrenoreceptor stimulation may influence diaphragmatic function and O2 extraction during reductions in O2 delivery (QO2di). METHODS The diaphragm was perfused using a constant flow pump with blood diverted from the left femoral artery. QO2di was reduced in a stepwise fashion by progressive reductions in pump flow. The tension generated by the contracting diaphragm (3 Hz), the critical O2 delivery (QO2di,c) below which O2 consumption (VO2di) becomes dependent on O2 supply and the oxygen extraction ratio at this critical point (ERc) were assessed in two groups of animals. Phenylephrine (10(-5) mol/L) was infused into the phrenic artery in one group and saline was infused in another group. RESULTS In the contracting diaphragm, VO2di was higher in the phenylephrine infused group than in the control group (5.2 +/- 0.5 vs 2.11 +/- 0.3 mL/min/100 g). QO2di,c and ERc were also higher in the phenylephrine group than in the control group (6.16 +/- 0.43 vs 3.1 +/- 0.5 mL/min/100 g and 0.87 +/- 0.035 vs 0.63 +/- 0.05, respectively). In the resting diaphragm, VO2di was not significantly different between the two groups and no critical oxygen delivery could be identified in either group. CONCLUSIONS These results indicate that alpha-adrenoreceptor activation may increase the tension generated by the diaphragm as well as its oxygen consumption and oxygen extraction. Although this may be beneficial during moderate reductions in oxygen delivery, in more severe shock states, activation of these receptors by endogenous or exogenously administered catecholamines may hasten the development of delivery limitation of VO2di and compromise the ability to sustain ventilation.

UI	MeSH Term	Description	Entries
D010101	Oxygen Consumption	The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)	Consumption, Oxygen,Consumptions, Oxygen,Oxygen Consumptions
D010656	Phenylephrine	An alpha-1 adrenergic agonist used as a mydriatic, nasal decongestant, and cardiotonic agent.	(R)-3-Hydroxy-alpha-((methylamino)methyl)benzenemethanol,Metaoxedrin,Metasympatol,Mezaton,Neo-Synephrine,Neosynephrine,Phenylephrine Hydrochloride,Phenylephrine Tannate,Neo Synephrine,Tannate, Phenylephrine
D012131	Respiratory Insufficiency	Failure to adequately provide oxygen to cells of the body and to remove excess carbon dioxide from them. (Stedman, 25th ed)	Acute Hypercapnic Respiratory Failure,Acute Hypoxemic Respiratory Failure,Hypercapnic Acute Respiratory Failure,Hypercapnic Respiratory Failure,Hypoxemic Acute Respiratory Failure,Hypoxemic Respiratory Failure,Respiratory Depression,Respiratory Failure,Ventilatory Depression,Depressions, Ventilatory,Failure, Hypercapnic Respiratory,Failure, Hypoxemic Respiratory,Failure, Respiratory,Hypercapnic Respiratory Failures,Hypoxemic Respiratory Failures,Respiratory Failure, Hypercapnic,Respiratory Failure, Hypoxemic,Respiratory Failures
D003964	Diaphragm	The musculofibrous partition that separates the THORACIC CAVITY from the ABDOMINAL CAVITY. Contraction of the diaphragm increases the volume of the thoracic cavity aiding INHALATION.	Respiratory Diaphragm,Diaphragm, Respiratory,Diaphragms,Diaphragms, Respiratory,Respiratory Diaphragms
D004195	Disease Models, Animal	Naturally-occurring or experimentally-induced animal diseases with pathological processes analogous to human diseases.	Animal Disease Model,Animal Disease Models,Disease Model, Animal
D004285	Dogs	The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)	Canis familiaris,Dog
D004353	Drug Evaluation, Preclinical	Preclinical testing of drugs in experimental animals or in vitro for their biological and toxic effects and potential clinical applications.	Drug Screening,Evaluation Studies, Drug, Pre-Clinical,Drug Evaluation Studies, Preclinical,Drug Evaluations, Preclinical,Evaluation Studies, Drug, Preclinical,Evaluation, Preclinical Drug,Evaluations, Preclinical Drug,Medicinal Plants Testing, Preclinical,Preclinical Drug Evaluation,Preclinical Drug Evaluations,Drug Screenings,Screening, Drug,Screenings, Drug
D000316	Adrenergic alpha-Agonists	Drugs that selectively bind to and activate alpha adrenergic receptors.	Adrenergic alpha-Receptor Agonists,alpha-Adrenergic Receptor Agonists,Adrenergic alpha-Agonist,Adrenergic alpha-Receptor Agonist,Receptor Agonists, Adrenergic alpha,Receptor Agonists, alpha-Adrenergic,alpha-Adrenergic Agonist,alpha-Adrenergic Agonists,alpha-Adrenergic Receptor Agonist,Adrenergic alpha Agonist,Adrenergic alpha Agonists,Adrenergic alpha Receptor Agonist,Adrenergic alpha Receptor Agonists,Agonist, Adrenergic alpha-Receptor,Agonist, alpha-Adrenergic,Agonist, alpha-Adrenergic Receptor,Agonists, Adrenergic alpha-Receptor,Agonists, alpha-Adrenergic,Agonists, alpha-Adrenergic Receptor,Receptor Agonist, alpha-Adrenergic,Receptor Agonists, alpha Adrenergic,alpha Adrenergic Agonist,alpha Adrenergic Agonists,alpha Adrenergic Receptor Agonist,alpha Adrenergic Receptor Agonists,alpha-Agonist, Adrenergic,alpha-Agonists, Adrenergic,alpha-Receptor Agonist, Adrenergic,alpha-Receptor Agonists, Adrenergic
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia