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Sex differences in hormone-sensitive lipase expression, activity, and phosphorylation in skeletal muscle at rest and during exercise

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningfagfællebedømt

  • Carsten Roepstorff
  • Morten Donsmark
  • Maja Thiele
  • Bodil Vistisen
  • Greg Stewart
  • Kristian Vissing
  • Peter Schjerling
  • D. Grahame Hardie
  • Henrik Galbo
  • Kiens, Bente
Women have been shown to use more intramuscular triacylglycerol (IMTG) during exercise than men. To investigate whether this could be due to sex-specific regulation of hormone-sensitive lipase (HSL) and to use sex comparison as a model to gain further insight into HSL regulation, nine women and eight men performed bicycle exercise (90 min, 60% Vo(2peak)), and skeletal muscle HSL expression, phosphorylation, and activity were determined. Supporting previous findings, basal IMTG content (P < 0.001) and net IMTG decrease during exercise (P < 0.01) were higher in women than in men and correlated significantly (r = 0.72, P = 0.001). Muscle HSL mRNA (80%, P = 0.11) and protein content (50%, P < 0.05) were higher in women than in men. HSL total activity increased during exercise (47%, P < 0.05) but did not differ between sexes. Accordingly, HSL specific activity (HSL activity per HSL protein content) increased during exercise (62%, P < 0.05) and was generally higher in men than in women (82%, P < 0.05). A similar pattern was observed for HSL Ser(659) phosphorylation, suggesting a role in regulation of HSL activity. Likewise, plasma epinephrine increased during exercise (P < 0.05) and was higher in men than in women during the end of the exercise bout (P < 0.05). We conclude that, although HSL expression and Ser(659) phosphorylation in skeletal muscle during exercise is sex specific, total muscle HSL activity measured in vitro was similar between sexes. The higher basal IMTG content in women compared with men is therefore the best candidate to explain the higher IMTG net hydrolysis during exercise in women.
OriginalsprogEngelsk
TidsskriftAmerican Journal of Physiology: Endocrinology and Metabolism
Vol/bind291
Udgave nummer5
Sider (fra-til)E1106-E1114
Antal sider9
ISSN0193-1849
DOI
StatusUdgivet - 2006

Bibliografisk note

PUF 2006 5200 019

ID: 314133