Myosin phenotype and bioenergetic characteristics of rat respiratory muscles
Myosin phenotype and bioenergetic characteristics of rat respiratory muscles
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DOI：
10.1097/00005768-199712000-00005
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发表时间：
1997-12-01
期刊：
影响因子：
--
通讯作者：
Prezant, D
中科院分区：
文献类型：
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作者：
Powers, SK;Demirel, HA;Prezant, D
这些实验检查了大鼠呼吸肌中的肌球蛋白表型和生物能酶活性。从成年雌性Sprague-Dawley大鼠（N = 8）中取出肌肉样品，并进行分析，以测定肌球蛋白重链（MHC）和轻链（MLC）亚型含量以及肌原纤维ATP酶（mATP酶）、柠檬酸合酶（CS;克雷布斯循环酶）和乳酸脱氢酶（LDH;糖酵解酶）的活性。分析表明，CS活性和%I型MHC和%IId MHC亚型是更大的肋膈（CO-D）与脚膈（CR-D）相比。相反，CR-D中的% IIb型MHC高于CO-D中的% IIb型MHC。与胸骨旁肋间肌（PI）、外肋间肌（EI）、内肋间肌（II）、腹直肌（RA）和胸锁乳突肌（SM）相比，CO-D和CR-D的LDH和mATPase活性均较低。CO-D和CR-D的CS活性、%I型MHC、%IIa型MHC和慢碱性MLC与总碱性MLC的比值（1 s/1 s + If + 3f）均高于其他呼吸肌。RA的IIb型MHC活性最高（P < 0.05），CS活性最低。最后，CS活性，mATP酶活性，MHC表型之间没有差异PI，EI，II，SM肌肉。这些生物化学性质的差异为呼吸泵的肌肉提供了功能性质的巨大多样性。
These experiments examined the myosin phenotype and bioenergetic enzyme activities in rat respiratory muscles. Muscle samples were removed from adult female Sprague-Dawley rats (N = 8) and analyzed to determine the myosin heavy chain (MHC) and light chain (MLC) isoform content as well as the activities of myofibrillar ATPase (mATPase), citrate synthase (CS; Krebs cycle enzyme), and lactate dehydrogenase (LDH; glycolytic enzyme). Analysis revealed that CS activity and the % type I MHC and %IId MHC isoforms were greater in the costal diaphragm (CO-D) compared with those in the crural diaphragm (CR-D). In contrast, the % type IIb MHC was higher in the CR-D compared with that in the CO-D. LDH and mATPase activity were lower in both the CO-D and CR-D compared with that in the parasternal intercostals (PI), external intercostals (EI), internal intercostals (II), rectus abdominis (RA), and sternomastoid (SM) muscles. CS activity, % type I MHC, %IIa MHC, and the ratio of slow to total alkali MLC (1s/1s + If + 3f) were greater in the CO-D and CR-D compared with those in all other respiratory muscles. The RA contained the highest (P < 0.05) % type IIb MHC and lowest CS activity compared with that in all other muscles. Finally, CS activity, mATPase activity, and MHC phenotype did not differ among the PI, EI, II, and SM muscles. These differences in biochemical properties provide the muscles of the respiratory pump with great versatility in functional properties.