脓毒症进展过程中大鼠心脏二氢吡啶受体的细胞内重新分布

Intracellular redistribution of dihydropyridine receptor in the rat heart during the progression of sepsis.

作者信息

Hsu Chin, Wu Guang, Yang Shaw-Lang, Hsu Hseng-Kuang, Yang Rei-Cheng, Tang Chaoshu, Liu Maw-Shung

机构信息

Department of Physiology, Graduate Institute of Physiology and Molecular Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.

出版信息

J Surg Res. 2007 Aug;141(2):146-52. doi: 10.1016/j.jss.2006.05.042. Epub 2007 May 11.

DOI:10.1016/j.jss.2006.05.042

PMID:17499274

Abstract

BACKGROUND

Dihydropyridine receptor (DHPR) regulates the rate and force of cardiac muscle contraction. This study examined the alteration in the intracellular redistribution of DHPR and its association with the development of the two distinct cardiodynamic states in the rat heart during the progression of sepsis.

MATERIAL AND METHODS

Sepsis was induced by cecal ligation and puncture (CLP). DHPRs were assayed using [(3)H]PN200-100 binding and photoaffinity labeling with [(3)H]azidopine followed by polyacrylamide gel electrophoresis.

RESULTS

[(3)H]PN200-110 binding shows that during the early hyperdynamic phase of sepsis (9 h post-CLP), the Bmax was increased by 27% in sarcolemma while decreased by 24% in light vesicle. During the late hypodynamic phase of sepsis (18 h post-CLP), the Bmax was decreased by 39% in sarcolemma but increased by 59% in light vesicle. The sum of the Bmax for both membrane fractions was increased by 16% during early sepsis while decreased by 17% during late sepsis. Photoaffinity labeling shows that the incorporation of [(3)H]azidopine into 165 kDa peptides during early sepsis was increased by 28% in sarcolemma whereas decreased by 23% in light vesicle. During late sepsis, the incorporation was decreased by 38% in sarcolemma but increased by 46% in light vesicle. The sum of the 165 kDa peptides for both membrane fractions was increased by 13% during early while decreased by 13% during late sepsis.

CONCLUSIONS

These data indicate that DHPRs in the rat heart were externalized from light vesicles to sarcolemma during the early hyperdynamic phase whereas they were internalized from surface membranes to intracellular sites during the late hypodynamic phase of sepsis. Furthermore, DHPRs were overexpressed during early sepsis while they were underexpressed during late sepsis. Alterations in the expression and intracellular redistribution of DHPRs may contribute to the development of the biphasic cardiodynamic states during the progression of sepsis.

摘要

背景

二氢吡啶受体（DHPR）调节心肌收缩的速率和力量。本研究检测了脓毒症进展过程中大鼠心脏中DHPR细胞内重新分布的变化及其与两种不同心脏动力学状态发展的关系。

材料与方法

采用盲肠结扎穿刺术（CLP）诱导脓毒症。使用[³H]PN200 - 100结合法以及用[³H]叠氮平进行光亲和标记，随后进行聚丙烯酰胺凝胶电泳来检测DHPR。

结果

[³H]PN200 - 110结合显示，在脓毒症早期高动力阶段（CLP后9小时），肌膜中的Bmax增加了27%，而轻囊泡中的Bmax降低了24%。在脓毒症晚期低动力阶段（CLP后18小时），肌膜中的Bmax降低了39%，而轻囊泡中的Bmax增加了59%。两个膜组分的Bmax总和在脓毒症早期增加了16%，而在脓毒症晚期降低了17%。光亲和标记显示，在脓毒症早期，[³H]叠氮平掺入165 kDa肽段的量在肌膜中增加了28%，而在轻囊泡中降低了23%。在脓毒症晚期，肌膜中的掺入量降低了38%，而轻囊泡中的掺入量增加了46%。两个膜组分的165 kDa肽段总和在早期增加了13%，而在脓毒症晚期降低了13%。