Differential regulation and recovery of intracellular Ca2+ in cerebral and small mesenteric arterial smooth muscle cells of simulated microgravity rat |
| |
Authors: | Xue Jun-Hui Chen Lian-Hong Zhao Hua-Zhou Pu Yong-Dong Feng Han-Zhong Ma Yu-Guang Ma Jin Chang Yao-Ming Zhang Zuo-Ming Xie Man-Jiang |
| |
Institution: | Department of Aerospace Clinical Medicine, Key Laboratory of Aerospace Medicine of Ministry of Education, Fourth Military Medical University, Xi'an, Shaanxi Province, China. |
| |
Abstract: | BackgroundThe differential adaptations of cerebrovasculature and small mesenteric arteries could be one of critical factors in postspaceflight orthostatic intolerance, but the cellular mechanisms remain unknown. We hypothesize that there is a differential regulation of intracellular Ca2+ determined by the alterations in the functions of plasma membrane CaL channels and ryanodine-sensitive Ca2+ releases from sarcoplasmic reticulum (SR) in cerebral and small mesenteric vascular smooth muscle cells (VSMCs) of simulated microgravity rats, respectively.Methodology/Principal FindingsSprague-Dawley rats were subjected to 28-day hindlimb unweighting to simulate microgravity. In addition, tail-suspended rats were submitted to a recovery period of 3 or 7 days after removal of suspension. The function of CaL channels was evaluated by patch clamp and Western blotting. The function of ryanodine-sensitive Ca2+ releases in response to caffeine were assessed by a laser confocal microscope. Our results indicated that simulated microgravity increased the functions of CaL channels and ryanodine-sensitive Ca2+ releases in cerebral VSMCs, whereas, simulated microgravity decreased the functions of CaL channels and ryanodine-sensitive Ca2+ releases in small mesenteric VSMCs. In addition, 3- or 7-day recovery after removal of suspension could restore the functions of CaL channels and ryanodine-sensitive Ca2+ releases to their control levels in cerebral and small mesenteric VSMCs, respectively.ConclusionsThe differential regulation of CaL channels and ryanodine-sensitive Ca2+ releases in cerebral and small mesenteric VSMCs may be responsible for the differential regulation of intracellular Ca2+, which leads to the altered autoregulation of cerebral vasculature and the inability to adequately elevate peripheral vascular resistance in postspaceflight orthostatic intolerance. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|