Tomera J F, Harakal C
J Cardiovasc Pharmacol. 1982 Jul-Aug;4(4):592-600. doi: 10.1097/00005344-198207000-00010.
The rate constants (-k) of Ca2+ from cellular compartments of intact smooth muscle cells of thoracic aorta of normotensive, renal hypertensive, and cadmium hypertensive rabbits were studied by 45Ca efflux and by employing norepinephrine (NE, 5.9 X 10(-7) M). Tissues from hypertensive animals showed an increased rate of release of 45Ca over a 5-h unloading period when compared to normotensive controls. Three exchangeable compartments were found to contribute to the total kinetic efflux curve for all groups. The Ca2+ fraction in compartments I and II showed an increased rate of Ca2+ release for the hypertensive subgroups. Although the rates were slowed for tissues treated with NE prior to efflux, the rates of the hypertensive subgroups were increased compared to the normotensive group. Pretreatment of aortic segments with NE caused an overall increase in 45Ca activity of the incubation medium and may explain the slowed rates attained in the efflux analyses. Influx studies showed that tissues from hypertensive animals had a greater uptake of 45Ca than did the normotensive controls. Such data may represent a larger exchangeable component in aortae from the hypertensive subgroups. These findings indicate differences in the rates of Ca2+ release from intact smooth muscle cells of hypertensive rabbits.
通过45Ca外流并使用去甲肾上腺素（NE，5.9×10(-7)M），研究了正常血压、肾性高血压和镉性高血压兔胸主动脉完整平滑肌细胞各细胞内区室中Ca2+的速率常数（-k）。与正常血压对照组相比，高血压动物的组织在5小时的卸载期内45Ca释放速率增加。发现所有组的总动力学外流曲线有三个可交换区室起作用。高血压亚组的I区和II区室中的Ca2+部分显示Ca2+释放速率增加。尽管在外流前用NE处理的组织速率减慢，但高血压亚组的速率与正常血压组相比有所增加。用NE预处理主动脉段导致孵育培养基中45Ca活性总体增加，这可能解释了外流分析中达到的速率减慢。内流研究表明，高血压动物的组织比正常血压对照组对45Ca的摄取更多。这些数据可能代表高血压亚组主动脉中更大的可交换成分。这些发现表明高血压兔完整平滑肌细胞中Ca2+释放速率存在差异。
