Rhythmic contraction generates adjustable passive stiffness in rabbit detrusor
Rhythmic contraction generates adjustable passive stiffness in rabbit detrusor
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DOI：
10.1152/japplphysiol.01079.2009
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发表时间：
2010-03-01
影响因子：
3.3
通讯作者：
Speich, John E.
中科院分区：
文献类型：
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作者：
Almasri, Atheer M.;Ratz, Paul H.;Speich, John E.
Almasri AM、Ratz PH、Bhatia H、Klausner AP、Speich JE。节律性收缩使兔子逼尿肌产生可调节的被动刚度。 J Appl Physiol 108: 544-553, 2010。首次发表于 2010 年 1 月 7 日； doi:10.1152/japplphyol.01079.2009.-气道和血管平滑肌的长度-张力 (L-T) 关系已被证明会随着时间的推移而适应长度变化。我们之前的研究表明，兔子逼尿肌平滑肌 (DSM) 的主动和被动 L-T 关系可以适应，并且 DSM 表现出可调节的被动刚度 (APS)，其特征是被动 L-T 曲线是应变和激活历史的函数。本研究表明，APS 产生的被动张力在很宽的长度范围内占总张力的很大一部分。我们之前的研究表明，短肌肉长度处 KCl 引起的最大收缩会产生 APS，与之前在这些长度上的测量相比，较长长度处伪稳态被动张力的增加揭示了这一点。本研究的目的是确定 APS 生成所涉及的机制。增加 KCl 诱导的收缩次数或收缩持续时间会增加 APS 的产生量。此外，一小部分APS在无钙溶液中被恢复，并且对一般的丝氨酸和苏氨酸蛋白激酶抑制剂十字孢菌素敏感。最重要的是，节律性收缩 (RC) 产生 APS，并且由于 RC 在人类膀胱中自发发生，因此可能确定 RC 的生理作用。
Almasri AM, Ratz PH, Bhatia H, Klausner AP, Speich JE. Rhythmic contraction generates adjustable passive stiffness in rabbit detrusor. J Appl Physiol 108: 544-553, 2010. First published January 7, 2010; doi:10.1152/japplphysiol.01079.2009.-The length-tension (L-T) relationships in airway and vascular smooth muscles have been shown to adapt with length changes over time. Our prior studies have shown that the active and passive L-T relationships in rabbit detrusor smooth muscle (DSM) can adapt and that DSM exhibits adjustable passive stiffness (APS) characterized by a passive L-T curve that is a function of strain and activation history. The present study demonstrates that passive tension due to APS can represent a substantial fraction of total tension over a broad length range. Our previous studies have shown that maximal KCl-induced contractions at short muscle lengths generate APS that is revealed by increased pseudo-steady-state passive tension at longer lengths compared with previous measurements at those lengths. The objective of the present study was to determine the mechanisms involved in APS generation. Increasing the number of KCl-induced contractions or the duration of a contraction increased the amount of APS generated. Furthermore, a fraction of APS was restored in calcium-free solution and was sensitive to the general serine and threonine protein kinase inhibitor staurosporine. Most importantly, rhythmic contraction (RC) generated APS, and because RC occurs spontaneously in human bladder, a physiological role for RC was potentially identified.