Ocular blood flow decreases during passive heat stress in resting humans.
Ocular blood flow decreases during passive heat stress in resting humans.
复制标题
DOI：
10.1186/1880-6805-32-23
复制
发表时间：
2013-12-06
影响因子：
3.1
通讯作者：
Hayashi N
中科院分区：
文献类型：
--
作者：
Ikemura T;Miyaji A;Kashima H;Yamaguchi Y;Hayashi N
热应激可引起多种生理变化，从而影响眼循环。本研究探讨了热应激对眼血流的影响。在两种水循环条件下测量12名健康受试者的眼血流、呼气末二氧化碳（PETCO 2）和血压：（1）在35°C（常温）下30 min和（2）在50°C下90 min（被动热应激）。用激光散斑血流图测量视网膜上级颞侧小动脉（STRA）、视网膜上级鼻侧小动脉（SNRA）和视网膜脉络膜血管（RCV）的血流速度。STRA和SNRA中的血流量由血流速度的横截面图的积分计算。通过向吸入气体中加入5%CO2将PETCO 2夹在正常体温水平。被动热应激对受试者的血压没有影响。被动热应激30、60和90 min后，RCV的血流速度明显低于常温水平，90 min时下降最大，为18 ± 3%（平均值±标准误）。被动热应激90 min后，STRA和SNRA的血流量显著下降，峰值分别下降14 ± 3%和14 ± 4%。这项研究的结果表明，被动热应激降低眼血流量，而不管血压或动脉CO2分压。
Heat stress induces various physiological changes and so could influence ocular circulation. This study examined the effect of heat stress on ocular blood flow. Ocular blood flow, end-tidal carbon dioxide (PETCO2) and blood pressure were measured for 12 healthy subjects wearing water-perfused tube-lined suits under two conditions of water circulation: (1) at 35°C (normothermia) for 30 min and (2) at 50°C for 90 min (passive heat stress). The blood-flow velocities in the superior temporal retinal arteriole (STRA), superior nasal retinal arteriole (SNRA), and the retinal and choroidal vessels (RCV) were measured using laser-speckle flowgraphy. Blood flow in the STRA and SNRA was calculated from the integral of a cross-sectional map of blood velocity. PETCO2 was clamped at the normothermia level by adding 5% CO2 to the inspired gas. Passive heat stress had no effect on the subjects’ blood pressures. The blood-flow velocity in the RCV was significantly lower after 30, 60 and 90 min of passive heat stress than the normothermic level, with a peak decrease of 18 ± 3% (mean ± SE) at 90 min. Blood flow in the STRA and SNRA decreased significantly after 90 min of passive heat stress conditions, with peak decreases of 14 ± 3% and 14 ± 4%, respectively. The findings of this study suggest that passive heat stress decreases ocular blood flow irrespective of the blood pressure or arterial partial pressure of CO2.
登录
查看更多内容
影响因子：
3.3
作者：
JONES, NL;ROBERTSON, DG;KANE, JW
通讯作者：
KANE, JW
影响因子：
3.3
作者：
ROWELL, LB;BRENGELMANN, GL;MURRAY, JA
通讯作者：
MURRAY, JA
影响因子：
3.4
作者：
ALM, A;BILL, A
通讯作者：
BILL, A
影响因子：
0.3
作者：
Hayashi, Naoyuki;Ikemura, Tsukasa;Someya, Nami
通讯作者：
Someya, Nami
影响因子：
3
作者：
Ikemura, Tsukasa;Someya, Nami;Hayashi, Naoyuki
通讯作者：
Hayashi, Naoyuki