Cold-acclimation leads to differential regulation of the steelhead trout (Oncorhynchus mykiss) coronary microcirculation.
Cold-acclimation leads to differential regulation of the steelhead trout (Oncorhynchus mykiss) coronary microcirculation.
复制标题
DOI：
10.1152/ajpregu.00353.2014
复制
发表时间：
2015-05
期刊：
影响因子：
--
通讯作者：
I. Costa;T. Hein;A. K. Gamperl
中科院分区：
文献类型：
--
作者：
I. Costa;T. Hein;A. K. Gamperl
鱼类血管阻力的调节在很大程度上是通过分离的大导血管进行研究的，然而组织灌注/血管阻力的变化主要是由小动脉的扩张/收缩介导的。因此，我们将哺乳动物分离的微血管技术应用于鱼类，并研究了几种药物如何影响适应1、5和10°C的虹鳟（Oncorhynchus mykiss）分离的冠状动脉（<150 μm ID）的张力/抗性。在10°C时，血管对腺苷（ADE; 61±8%）、硝普钠（SNP; 35±10%）和血清素（SER; 27±2%）呈浓度依赖性扩张（所有值均为最大反应）。在肾上腺素（EPI，扩张34±9%）和去甲肾上腺素（NE，扩张32±7%）浓度升高的血管中，观察到双相反应（轻度收缩然后扩张），而缓激素（BK，收缩12.5±3.5% vs扩张6±6%）的效果不那么明显。最后，暴露于乙酰胆碱后观察到轻度收缩（ACh; 6.5±1.4%），而内皮素(ET)-1引起强烈的剂量依赖性张力增加（收缩79±5%）。驯化温度对血管的反应性有不同的影响。与10°C相比，EPI、ADE、SER和SNP诱导的扩张在5°C和/或1°C时减少/消除。相比之下，驯化5°C和1°C增加了乙酰胆碱引起的最大收缩，血管对ET-1的敏感性（但不是最大反应）在1°C时更大。驯化温度对NE的响应没有影响，对BK的响应是可变的。
The regulation of vascular resistance in fishes has largely been studied using isolated large conductance vessels, yet changes in tissue perfusion/vascular resistance are primarily mediated by the dilation/constriction of small arterioles. Thus we adapted mammalian isolated microvessel techniques for use in fish and examined how several agents affected the tone/resistance of isolated coronary arterioles (<150 μm ID) from steelhead trout (Oncorhynchus mykiss) acclimated to 1, 5, and 10°C. At 10°C, the vessels showed a concentration-dependent dilation to adenosine (ADE; 61 ± 8%), sodium nitroprusside (SNP; 35 ± 10%), and serotonin (SER; 27 ± 2%) (all values maximum responses). A biphasic response (mild contraction then dilation) was observed in vessels exposed to increasing concentrations of epinephrine (EPI; 34 ± 9% dilation) and norepinephrine (NE; 32 ± 7% dilation), whereas the effect was less pronounced with bradykinin (BK; 12.5 ± 3.5% constriction vs. 6 ± 6% dilation). Finally, a mild constriction was observed after exposure to acetylcholine (ACh; 6.5 ± 1.4%), while endothelin (ET)-1 caused a strong dose-dependent increase in tone (79 ± 5% constriction). Acclimation temperature had varying effects on the responsiveness of vessels. The dilations induced by EPI, ADE, SER, and SNP were reduced/eliminated at 5°C and/or 1°C as compared with 10°C. In contrast, acclimation to 5 and 1°C increased the maximum constriction induced by ACh and the sensitivity of vessels to ET-1 (but not the maximum response) at 1°C was greater. Acclimation temperature had no effect on the response to NE, and responsiveness to BK was variable.