Hydrogen peroxide alters sternohyoid muscle function

Upper airway ( UA ) dilator muscles are critical for the maintenance of airway patency. Injury or fatigue to this group of muscles, as observed in patients with obstructive sleep apnoea ( OSA ) and animal models of OSA , may leave the UA susceptible to collapse. Although the mechanisms underlying respiratory muscle dysfunction are not completely understood, there is strong evidence suggesting a link between increased production of reactive oxygen species and altered muscle function. The aim of this study was to examine the effects of H 2 O 2 on rat sternohyoid muscle function in vitro . Sternohyoid contractile and endurance properties were examined at 35°C under control or hypoxic conditions. Studies were conducted in the presence of varying concentrations of H 2 O 2 (0, 0.01, 0.1 and 1 mM). Muscle function was also examined in the presence of antioxidants [desferoxamine ( DFX ), catalase] and the reducing agent dithiothreitol ( DTT ). H 2 O 2 decreased muscle endurance in a concentration‐dependent manner. This was partially reversed by catalase, DFX and DTT . Our results suggest that oxidants may contribute to UA respiratory muscle dysfunction with implications for the control of UA patency in vivo .