Normalization of force generated by canine airway smooth muscles.
Normalization of force generated by canine airway smooth muscles.
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犬气道平滑肌产生的力正常化。
DOI：
10.1152/ajplung.1991.260.6.l522
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
Newman L. Stephens
中科院分区：
文献类型：
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作者：
He Jiang;A. Halayko;K. Rao;P. Cunningham;Newman L. Stephens
各种归一化方法被用来比较不同位置和成熟阶段的平滑肌产生的最大等长力(Po)。由于这些程序并不总是基于严格的原则，因此造成了混乱。为了获得一个不那么模糊的力产生指数，我们用电磁杠杆在体外测量了杂种犬气管(TSM)和支气管(BSM)的平滑肌的Po，并将其归一化为单位组织横截面上的力(组织应力)、总组织横截面上的单位肌肉横截面上的力(肌肉应力)和组织横截面上每单位肌球蛋白的力(肌球蛋白应力)。肌球蛋白在组织横截面积中的比例是由肌肉粗提物的十二烷基硫酸钠凝胶电泳法得出的。TSM的组织应力为1.499×10~(5)N/m~2+/-0.1(SE)，而BSM的组织应力仅为0.351×10~(5)N/m~2+/-0.05(SE)，相差4.27倍(P<0.01)。肌肉应力相差1.60倍(P<0.05)，这与形态计量学发现79+/-1.4%(SE)的气管条横截面为肌肉，而只有30+/-1.0%(SE)的支气管组织由肌肉占据有关。肌球蛋白在TSM和BSM的平均肌球蛋白含量相同，表明肌球蛋白在组织横截面中的总量本质上是肌细胞在总组织横截面中所占比例的函数。
A variety of normalizations have been employed to compare maximal isometric force (Po) produced by smooth muscles at different locations and stages of maturation. Because these procedures have not always been based on rigorous principles, confusion has resulted. To obtain a less ambiguous index of force production, we measured in vitro Po from mongrel canine tracheal (TSM) and bronchial (BSM) smooth muscle with an electromagnetic lever and normalized it to force per unit cross-sectional area of whole tissue (tissue stress), to force per unit cross-sectional area of muscle in the cross section of total tissue (muscle stress), and to force per fractional unit of myosin in the tissue cross section (myosin stress). Proportion of myosin in cross-sectional area of tissue was deduced from data obtained by sodium dodecyl sulfate gel electrophoresis of crude muscle extracts. For TSM, tissue stress was 1.499 X 10(5) N/m2 +/- 0.1 (SE), whereas it was only 0.351 X 10(5) N/m2 +/- 0.05 (SE) for BSM, representing a 4.27-fold difference (P less than 0.01). There was a 1.60-fold difference (P less than 0.05) in muscle stress, which was correlated to the morphometric finding that 79 +/- 1.4% (SE) of the tracheal strip cross section was muscle, whereas only 30 +/- 1.0% (SE) of bronchial tissue was occupied by muscle. Average myosin content was the same in smooth muscle cells of TSM and BSM, indicating that total amount of myosin in tissue cross sections was essentially a function of proportional area of muscle cells in total tissue cross sections.(ABSTRACT TRUNCATED AT 250 WORDS)