Functional alterations in cerebrovascular K+ and Ca2+ channels are comparable between simulated microgravity rat and SHR
Functional alterations in cerebrovascular K+ and Ca2+ channels are comparable between simulated microgravity rat and SHR
复制标题
模拟微重力大鼠和 SHR 脑血管 K 和 Ca2 通道的功能改变具有可比性
DOI：
10.1152/ajpheart.00074.2005
复制
发表时间：
2005-09-01
影响因子：
4.8
通讯作者：
Cheng, HW
中科院分区：
文献类型：
--
作者：
Xie, MJ;Zhang, LF;Cheng, HW
Exposure to microgravity leads to a sustained elevation in transmural pressure across the cerebral vasculature due to removal of hydrostatic pressure gradients. We hypothesized that ion channel remodeling in cerebral vascular smooth muscle cells (VSMCs) similar to that associated with hypertension may occur and play a role in upward autoregulation of cerebral vessels during microgravity. Sprague-Dawley rats were subjected to 4-wk tail suspension ( Sus) to simulate the cardiovascular effect of microgravity. Large-conductance Ca2+-activated K+ (BKCa), voltage-gated K+ (K-V), and L-type voltage-dependent Ca2+ (Ca-L) currents of Sus and control (Con) rat cerebral VSMCs were investigated with a whole cell voltage-clamp technique. Under the same experimental conditions, KV, BKCa, and Ca-L currents of cerebral VSMCs from adult spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY) were also investigated. K-V current density decreased in Sus rats vs. Con rats [1.07 +/- 0.14 (n = 22) vs. 1.31 +/- 0.28 (n = 16) pA/pF at +20 mV (P < 0.05)] and BKCa and Ca-L current densities increased [BKCa: 1.70 +/- 0.37 (n = 23) vs. 0.88 +/- 0.22 (n = 19) pA/pF at +20 mV (P < 0.05); Ca-L: -2.17 +/- 0.21 (n = 35) vs. -1.31 +/- 0.10 (n = 26) pA/pF at +10 mV (P < 0.05)]. Similar changes were also observed in SHR vs. WKY cerebral VSMCs: KV current density decreased [1.03 +/- 0.33 (n = 9) vs. 1.62 +/- 0.64 (n = 9) pA/pF at +20 mV (P < 0.05)] and BKCa and Ca-L current densities increased [BKCa: 2.54 +/- 0.47 (n = 11) vs. 1.12 +/- 0.33 (n = 12) pA/pF at +20 mV (P < 0.05); Ca-L: -3.99 +/- 0.53 (n = 12) vs. -2.28 +/- 0.20 (n = 10) pA/pF at +20 mV (P < 0.05)]. These findings support our hypothesis, and their impact on space cardiovascular research is discussed.
