Ladu M J, Kapsas H, Palmer W K
Exercise Research Division, College of Kinesiology, University of Illinois, Chicago 60680.
J Appl Physiol (1985). 1991 Aug;71(2):404-9. doi: 10.1152/jappl.1991.71.2.404.
Lipoprotein lipase (LPL) is regulated in a tissue-specific manner; exercise increases LPL activity in muscle at the same time it is reduced in adipose tissue. The purpose of this study was to determine the relationship between LPL activity and LPL mRNA in muscle and adipose tissue in rats exposed to one bout of exercise. Immediately after a 2-h swim, LPL activity [pmol free fatty acids (FFA).min-1.mg tissue-1] in the exercised animals was reduced 43% in adipose tissue (110 +/- 26 to 63 +/- 17) and increased almost twofold in the soleus muscle (203 +/- 26 to 383 +/- 59) compared with sedentary control animals. At the same time, LPL mRNA was reduced 42% in adipose tissue and increased 50 and 100% in the red vastus and white vastus muscles, respectively. Twenty-four hours after the swim, LPL activity had returned to control levels in adipose tissue and the soleus muscle. At hour 24 of recovery, LPL mRNA was still reduced 23% in the adipose tissue of exercised animals but was not significantly different between exercised and control animals in any of the muscle tissues analyzed. Changes in total RNA concentration could not account for the changes in relative LPL mRNA expression. The relationship between LPL enzyme activity and LPL mRNA in muscle and adipose tissue was +0.86 and +0.93 at 0 and 24 h postexercise, respectively. Thus the tissue-specific changes in enzyme activity induced by exercise could be mediated, in part, through pretranslational control.
脂蛋白脂肪酶（LPL）以组织特异性方式受到调节；运动可增加肌肉中的LPL活性，同时降低脂肪组织中的LPL活性。本研究的目的是确定一次性运动大鼠的肌肉和脂肪组织中LPL活性与LPL mRNA之间的关系。在2小时游泳结束后立即检测发现，与久坐不动的对照动物相比，运动动物脂肪组织中的LPL活性[皮摩尔游离脂肪酸（FFA）·分钟⁻¹·毫克组织⁻¹]降低了43%（从110±26降至63±17），而比目鱼肌中的LPL活性几乎增加了两倍（从203±26增至383±59）。与此同时，脂肪组织中LPL mRNA降低了42%，而红股四头肌和白股四头肌中的LPL mRNA分别增加了50%和100%。游泳24小时后，脂肪组织和比目鱼肌中的LPL活性恢复到对照水平。在恢复的第24小时，运动动物脂肪组织中的LPL mRNA仍比对照降低23%，但在所分析的任何肌肉组织中，运动动物与对照动物之间无显著差异。总RNA浓度的变化不能解释LPL mRNA相对表达的变化。运动后0小时和24小时，肌肉和脂肪组织中LPL酶活性与LPL mRNA之间的关系分别为+0.86和+0.93。因此，运动诱导的酶活性组织特异性变化可能部分通过翻译前控制介导。
