Roepstorff Carsten, Donsmark Morten, Thiele Maja, Vistisen Bodil, Stewart Greg, Vissing Kristian, Schjerling Peter, Hardie D Grahame, Galbo Henrik, Kiens Bente
The Copenhagen Muscle Research Centre, Department of Human Physiology, Institute of Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark.
Am J Physiol Endocrinol Metab. 2006 Nov;291(5):E1106-14. doi: 10.1152/ajpendo.00097.2006. Epub 2006 Jul 5.
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.
研究表明，女性在运动过程中比男性更多地利用肌肉内三酰甘油（IMTG）。为了研究这是否可能归因于激素敏感脂肪酶（HSL）的性别特异性调节，并将性别比较作为一种模型来进一步深入了解HSL调节，9名女性和8名男性进行了自行车运动（90分钟，60%的最大摄氧量），并测定了骨骼肌HSL的表达、磷酸化和活性。支持先前的研究结果，女性的基础IMTG含量（P<0.001）和运动期间IMTG的净减少量（P<0.01）高于男性，且两者显著相关（r = 0.72，P = 0.001）。女性的肌肉HSL mRNA（高80%，P = 0.11）和蛋白质含量（高50%，P<0.05）高于男性。运动期间HSL的总活性增加（47%，P<0.05），但性别之间没有差异。因此，HSL的比活性（每HSL蛋白质含量的HSL活性）在运动期间增加（62%，P<0.05），并且总体上男性高于女性（高82%，P<0.05）。HSL丝氨酸（Ser）659磷酸化也观察到类似模式，表明其在HSL活性调节中起作用。同样，运动期间血浆肾上腺素增加（P<0.05），并且在运动结束时男性高于女性（P<0.05）。我们得出结论，尽管运动期间骨骼肌中HSL的表达和Ser659磷酸化具有性别特异性，但体外测量的总肌肉HSL活性在性别之间是相似的。因此，与男性相比，女性较高的基础IMTG含量是解释女性运动期间较高IMTG净水解的最佳候选因素。
