McDonald, FB,Skelly, JR,O'Halloran, KD

2015

January

Oral Diseases

The beta(2)-adrenoceptor agonist terbutaline recovers rat pharyngeal dilator muscle force decline during severe hypoxia

Validated

WOS: 6 ()

obstructive sleep apnoea syndrome hypoxia sternohyoid (2)-adrenoceptor agonist OBSTRUCTIVE SLEEP-APNEA FATIGUED CANINE DIAPHRAGM CHRONIC INTERMITTENT HYPOXIA SKELETAL-MUSCLE UPPER AIRWAY CONTRACTILE PROPERTIES BETA-ADRENOCEPTORS FIBER-TYPE BETA-2-RECEPTOR AGONIST CLENBUTEROL

21

121

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RationaleObstructive sleep apnoea syndrome (OSAS) is a debilitating condition characterized by recurrent occlusions of the pharyngeal airway during sleep accompanied by arterial hypoxaemia. Upper airway muscle dysfunction is implicated in the pathophysiology of OSAS. Pharmacological agents that improve muscle contractile and endurance properties may have therapeutic value.AimWe tested the hypothesis that the (2)-adrenoceptor agonist terbutaline improves rat sternohyoid muscle performance especially during hypoxic stress.MethodsIsometric contractile and endurance properties were examined ex vivo in Krebs solution at 35 degrees C. Muscles were incubated in tissue baths under hyperoxic (95% O-2/5% CO2) conditions in the absence (control) or presence of the (2)-adrenoceptor agonist terbutaline (1M). In additional experiments under hypoxic (95% N-2/5% CO2) conditions, the effects of terbutaline were examined in the presence of the -adrenoceptor antagonist propranolol (1M).ResultsHypoxia significantly impaired sternohyoid force production. Terbutaline completely recovered hypoxic depression of force, an effect that was blocked by co-application with propranolol.ConclusionThe (2)-adrenoceptor agonist terbutaline completely recovers hypoxic depression of upper airway muscle force. (2)-adrenoceptor agonists warrant investigation in animal models of OSAS reporting upper airway and diaphragm muscle dysfunction.

10.1111/odi.12247