TY - GEN
T1 - Intermittent hypoxia impairs pharyngeal dilator muscle function in male but not female rats
AU - Skelly, J. Richard
AU - Bradford, Aidan
AU - O'Halloran, Ken D.
PY - 2010
Y1 - 2010
N2 - Upper airway muscle dysfunction is implicated in obstructive sleep apnoea syndrome (OSAS), a common respiratory disorder associated with recurrent hypoxaemia. The prevalence of OSAS is higher in males than females. We tested the hypothesis that sex differences exist in the effects of intermittent hypoxia on upper airway muscle function. Adult Wistar rats were exposed to intermittent hypoxia (IH, 90s air/90s N2; 5% O2 at nadir) or sham treatment for 8 hours/day for 9 days. Following treatments, animals were killed humanely and isometric contractile properties of the sternohyoid (SH) muscle were examined at 35OC in vitro. Force-frequency relationship was determined at stimulus frequencies ranging 10-100Hz. In male rats, SH peak force was decreased in IH-treated male rats [22.7 ± 0.8 vs. 15.9 ± 0.9 N/cm2, sham (n = 8) vs. IH (n = 8), p < 0.001 ANOVA]. Conversely, in female rats, IH treatment had no effect on SH peak force [21.0 ± 1.2 vs. 19.8 ± 0.8 N/cm2, sham (n = 8) vs. IH (n = 8), p > 0.05 ANOVA]. We conclude that IH-induced impairment of pharyngeal dilator muscle performance may contribute to OSAS.
AB - Upper airway muscle dysfunction is implicated in obstructive sleep apnoea syndrome (OSAS), a common respiratory disorder associated with recurrent hypoxaemia. The prevalence of OSAS is higher in males than females. We tested the hypothesis that sex differences exist in the effects of intermittent hypoxia on upper airway muscle function. Adult Wistar rats were exposed to intermittent hypoxia (IH, 90s air/90s N2; 5% O2 at nadir) or sham treatment for 8 hours/day for 9 days. Following treatments, animals were killed humanely and isometric contractile properties of the sternohyoid (SH) muscle were examined at 35OC in vitro. Force-frequency relationship was determined at stimulus frequencies ranging 10-100Hz. In male rats, SH peak force was decreased in IH-treated male rats [22.7 ± 0.8 vs. 15.9 ± 0.9 N/cm2, sham (n = 8) vs. IH (n = 8), p < 0.001 ANOVA]. Conversely, in female rats, IH treatment had no effect on SH peak force [21.0 ± 1.2 vs. 19.8 ± 0.8 N/cm2, sham (n = 8) vs. IH (n = 8), p > 0.05 ANOVA]. We conclude that IH-induced impairment of pharyngeal dilator muscle performance may contribute to OSAS.
UR - https://www.scopus.com/pages/publications/77952311141
U2 - 10.1007/978-1-4419-5692-7_58
DO - 10.1007/978-1-4419-5692-7_58
M3 - Conference proceeding
C2 - 20217367
AN - SCOPUS:77952311141
SN - 9781441956910
T3 - Advances in Experimental Medicine and Biology
SP - 285
EP - 287
BT - New Frontiers in Respiratory Control
A2 - Homma, Ikuo
A2 - Onimaru, Hiroshi
A2 - Fukuchi, Yoshinosuke
ER -