Yoshida M, Ueda S, Machida J, Ikegami K
Department of Urology, Kumamoto University Medical School, Japan.
Urol Int. 1989;44(3):147-51. doi: 10.1159/000281491.
To examine the intracellular calcium content of the vascular smooth muscle in the chronic phase of renovascular hypertension, the effects of caffeine on isolated aortic, renal and iliac arterial strips were evaluated in two-kidney, one-clip renovascular hypertension in rabbits. 10 weeks after left renal artery constriction in the constricted group, systemic blood pressure (BP) was significantly higher than in the control group, but plasma renin activity was similar to the control value. The amplitude of caffeine-induced contraction of various vascular strips in the constricted group gradually increased and, at 10 weeks, this was higher in the constricted group than in the control group. In the constricted group, sodium loading produced BP elevation and increased the amplitude of caffeine-induced contraction, whereas sodium constriction decreased BP and the amplitude. In the control group, altered sodium intake did not affect BP and the amplitude of caffeine-induced contraction. These results suggest that in the chronic phase of renovascular hypertension, the increased caffeine-sensitive intracellular calcium store on vascular smooth muscle, which is increased by sodium loading and is decreased by sodium restriction, may contribute to the maintenance of hypertension.
为了研究肾血管性高血压慢性期血管平滑肌的细胞内钙含量，在双肾单夹肾血管性高血压兔模型中评估了咖啡因对离体主动脉、肾动脉和髂动脉条的作用。在狭窄组左肾动脉缩窄10周后，全身血压（BP）显著高于对照组，但血浆肾素活性与对照值相似。狭窄组中咖啡因诱导的各种血管条收缩幅度逐渐增加，在10周时，狭窄组的收缩幅度高于对照组。在狭窄组中，钠负荷导致血压升高并增加咖啡因诱导的收缩幅度，而钠限制则降低血压和收缩幅度。在对照组中，改变钠摄入量不影响血压和咖啡因诱导的收缩幅度。这些结果表明，在肾血管性高血压慢性期，血管平滑肌上对咖啡因敏感的细胞内钙储存增加，其因钠负荷而增加，因钠限制而减少，这可能有助于维持高血压。
