Vargas F, Fernández-Rivas A, García Estañ J, García del Rio C
Departamento de Fisiología, Facultade de Medicina, Granada, España.
Pharmacology. 1995 Nov;51(5):308-14. doi: 10.1159/000139340.
The effects of hyper- and hypothyroidism on the vasorelaxing responses to acetylcholine (ACh), sodium nitroprusside (NP), and CaCl2 were investigated in aortic strips and isolated perfused kidneys. The renal vascular reactivity to ACh and NP was increased in hyperthyroid rats, whereas the concentration-response curve to ACh in hypothyroid rats was flattened. In the renal vasculature from hypothyroid rats, NP produced a dual response: vasoconstriction at low doses and vasodilation at medium to high doses. Aortic strips from hyperthyroid rats showed an increased response to ACh without significant differences between hypothyroid and control groups. Aortic strips from all three experimental groups showed a similar relaxing response to CaCl2. These results indicate that: (1) the raised arterial pressure of hyperthyroid rats is not associated with a reduced endothelium-dependent and calcium-induced vasodilation, and (2) the changes in responsiveness to vasodilators in resistance vessels from hyper- and hypothyroid rats may play a role in the increased and decreased peripheral vascular resistances, respectively, previously reported in such animals.
在主动脉条和离体灌注肾脏中研究了甲状腺功能亢进和减退对乙酰胆碱（ACh）、硝普钠（NP）和氯化钙的血管舒张反应的影响。甲状腺功能亢进大鼠对ACh和NP的肾血管反应性增加，而甲状腺功能减退大鼠对ACh的浓度-反应曲线变平。在甲状腺功能减退大鼠的肾血管系统中，NP产生双相反应：低剂量时血管收缩，中高剂量时血管舒张。甲状腺功能亢进大鼠的主动脉条对ACh的反应增强，甲状腺功能减退组与对照组之间无显著差异。所有三个实验组的主动脉条对氯化钙的舒张反应相似。这些结果表明：（1）甲状腺功能亢进大鼠升高的动脉压与内皮依赖性和钙诱导的血管舒张降低无关；（2）甲状腺功能亢进和减退大鼠阻力血管对血管舒张剂反应性的变化可能分别在先前报道的此类动物外周血管阻力增加和降低中起作用。
