Effects of controlled mechanical ventilation on respiratory muscle contractile properties in rabbits
Effects of controlled mechanical ventilation on respiratory muscle contractile properties in rabbits
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DOI：
10.1007/s00134-002-1548-3
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发表时间：
2003-01-01
影响因子：
38.9
通讯作者：
Prefaut, C
中科院分区：
文献类型：
--
作者：
Capdevila, X;Lopez, S;Prefaut, C
目的：我们研究了超过48小时的机械通气对家兔呼吸肌收缩特性和纤维类型适应的影响。设计和设置：在大学实验室的实验前瞻性研究。动物和干预措施：将19只兔子随机分配到两组：对照组（n = 10）或机械通气（MV; n = 9）51 +/-3小时。测量和结果：呼吸肌收缩特性进行了分析之前和之后的疲劳协议，在两块肌肉中使用体内等长1-s强直收缩特性：峰值强直力，收缩时间，松弛时间，和总收缩时间。两种肌纤维类型的比例，直径和横截面积使用ATP酶染色测量。MV兔在两块肌肉中都表现出显著的体重减轻，同时伴有峰值强直力的降低（对照组和MV动物的膈肌分别为9.96 +/-3.2与7.44 +/-2.2 N），抗疲劳指数，和增加的舒张时间（对照和MV动物的隔膜为57.5 +/-8.7对85.8 +/-9.4 ms）和收缩时间。MV组的这些损伤在疲劳跑后恶化。两种肌肉的IIa和IIb型纤维明显萎缩，但I型纤维的横截面积稳定。结论：机械通气在兔产生的膈肌和第五外肋间肌的收缩特性的改变，增加两个肌肉疲劳，并促进II型纤维的萎缩。
Objective: We examined in rabbits the effects of more than 48 h of mechanical ventilation on the contractile properties and fiber type adaptations of the respiratory muscles. Design and setting: Experimental prospective study in a university laboratory. Animals and interventions: Nineteen rabbits were randomly allocated to two groups: control (n=10) or mechanically ventilated (MV; n=9) for 51 +/- 3 h. Measurements and results: Respiratory muscles contractile properties were analyzed before and after a fatigue protocol using in vivo isometric 1-s tetanic contraction characteristics in both muscles: peak tetanic force, contraction time, relaxation time, and total contraction time. Both muscle fiber type proportions, diameter, and cross-sectional areas were measured using ATPase staining. The MV rabbits showed significant weight loss in both muscles, accompanied by a reduced peak tetanic force (9.96 +/- 3.2 vs. 7.44 +/- 2.2 N for diaphragm of control and MV animals respectively), fatigue resistance index, and increased relaxation time (57.5 +/- 8.7 vs. 85.8 +/- 9.4 ms for diaphragm of control and MV animals) and contraction time. These impairments in the MV group worsened after the fatigue runs. Both muscle showed a significant atrophy of type IIa and IIb fibers but a stability in type I fibers cross-sectional area. Conclusions: Mechanical ventilation in rabbits produces alterations in contractile properties of the diaphragm and 5th external intercostal muscle, increases both muscles fatigue, and promotes atrophy of type II fibers.