Lower respiratory capacity in extraocular muscle mitochondria: evidence for intrinsic differences in mitochondrial composition and function.
Lower respiratory capacity in extraocular muscle mitochondria: evidence for intrinsic differences in mitochondrial composition and function.
复制标题
DOI：
10.1167/iovs.08-1911
复制
发表时间：
2009-01
影响因子：
4.4
通讯作者：
Andrade, Francisco H.
中科院分区：
文献类型：
--
作者：
Patel, Samir P.;Gamboa, Jorge L.;McMullen, Colleen A.;Rabchevsky, Alexander;Andrade, Francisco H.
眼外肌的持续活动是由丰富的线粒体支持的。这些细胞器可以通过增加呼吸复合体的含量来增强能量的产生。因此，我们验证了眼外肌线粒体比四肢肌线粒体呼吸更快的假设，因为呼吸复合体的含量更高。用体视学方法测定成年雄性SD大鼠小腿三头肌和眼外肌的线粒体膜密度。我们用克拉克型电极测量了分离的线粒体的呼吸频率。用分光光度法测定呼吸复合体I、II、IV的活性。用免疫印迹法检测呼吸复合体的含量。眼外肌线粒体3、4、5态呼吸频率比肢体肌线粒体低40-60%。眼外肌内线粒体膜密度与其他骨骼肌相似。在眼外肌线粒体中，络合物I和IV的活性较低(∼活性是三头肌的50%)，但它们的含量比∼高15-30%。复合体II的含量或活性或复合体III的含量没有差异。最后，复合体V在眼外肌线粒体中含量较少。我们的结果表明，尽管线粒体超微结构相似，但眼外肌线粒体的呼吸速度慢于肢体肌肉的线粒体。相反，我们发现电子传递链复合体的活性(I，IV)和含量(I，IV，V)存在差异。某些复合体的活性和含量之间的差异提示，与四肢肌相比，眼外肌中有不同的亚基亚基表达。
The constant activity of the extraocular muscles is supported by abundant mitochondria. These organelles could enhance energy production by increasing the content of respiratory complexes. Therefore, we tested the hypothesis that extraocular muscle mitochondria respire faster than those from limb muscles because of higher content of respiratory complexes. Inner mitochondrial membrane density was determined by stereological analysis of triceps surae (a limb muscle) and extraocular muscles of adult male Sprague-Dawley rats. We measured respiration rates of isolated mitochondria using a Clark-type electrode. The activity of respiratory complexes I, II and IV was determined by spectrophotometry. The content of respiratory complexes was estimated by western blot. State 3, 4 and 5 respiration rates in extraocular muscle mitochondria were 40-60% less than in limb muscle mitochondria. Extraocular muscle inner mitochondrial membrane density was similar to other skeletal muscles. Activity of complexes I and IV was less in extraocular muscle mitochondria (∼50% the activity in triceps), but their content was ∼15-30% higher. There was no difference in complex II content or activity, or complex III content. Finally, complex V was less abundant in extraocular muscle mitochondria. Our results demonstrate that extraocular muscle mitochondria respire at slower rates than mitochondria from limb muscles, despite similar mitochondrial ultrastructure. Instead, we found differences in the activity (I, IV) and content (I, IV, V) of electron transport chain complexes. The discrepancy between activity and content of some complexes is suggestive of alternative subunit isoform expression in the extraocular muscles compared to limb muscles.
登录
查看更多内容
影响因子：
4.3
作者：
Kavanagh, NI;Ainscow, EK;Brand, MD
通讯作者：
Brand, MD
DOI：
10.1016/0034-5687(81)90079-7
发表时间：
1981-01-01
期刊：
RESPIRATION PHYSIOLOGY
影响因子：
--
作者：
MATHIEU, O;KRAUER, R;WEIBEL, ER
通讯作者：
WEIBEL, ER
DOI：
10.1016/0034-5687(81)90078-5
发表时间：
1981-01-01
期刊：
RESPIRATION PHYSIOLOGY
影响因子：
--
作者：
HOPPELER, H;MATHIEU, O;WEIBEL, ER
通讯作者：
WEIBEL, ER
影响因子：
5.5
作者：
Anderson, EJ;Neufer, PD
通讯作者：
Neufer, PD
影响因子：
3.5
作者：
Hüttemann, M;Kadenbach, B;Grossman, LI
通讯作者：
Grossman, LI