Bershteĭn S A, Solov'ev A I, Stepanenko L G, Baziliuk O V
Fiziol Zh SSSR Im I M Sechenova. 1988 Apr;74(4):541-6.
In isolated smooth muscle of the rat portal vein removal of Mg2+ from perfusate induced rapid enhancement of frequency and amplitude of spontaneous contractions and decreased inhibiting effect of hypoxia on the smooth muscle contractile activity. Concomitant elevation of extracellular Ca2+ has no additional protective effect on the smooth muscle in hypoxia. Ten-fold lowering of Mg2+ content in buffer solution resulted in a significant rise in the tension of the smooth muscle activated by Ca2+. The data obtained suggest that protective effect of Mg2+-free solution on vascular smooth muscle in hypoxia may be mediated not only through increases intracellular Ca2+ concentration but also due to rising sensitivity of the smooth muscle cells contractile protein to Ca2+.
在大鼠门静脉的离体平滑肌中，从灌注液中去除Mg2+会导致自发收缩的频率和幅度迅速增加，并降低缺氧对平滑肌收缩活动的抑制作用。细胞外Ca2+的同时升高对缺氧状态下的平滑肌没有额外的保护作用。缓冲溶液中Mg2+含量降低10倍会导致Ca2+激活的平滑肌张力显著升高。所获得的数据表明，无Mg2+溶液对缺氧状态下血管平滑肌的保护作用可能不仅通过增加细胞内Ca2+浓度来介导，还可能是由于平滑肌细胞收缩蛋白对Ca2+的敏感性增加所致。
