Jesuś García J, Sánchez Olea R, Pasantes-Morales H
Institute of Cell Physiology, National A. University of Mexico, México D.F.
J Cell Biochem. 1991 Feb;45(2):207-12. doi: 10.1002/jcb.240450212.
Rabbit lymphocytes exposed to hyposmotic media first swell and then recover their initial volume within 6 min. During volume recovery, free amino acids (FAA) decrease from 451.1 to 208 nmoles/mg protein. Taurine was the dominating FAA, accounting for 70% of the FAA pool. The time course of 3H-taurine release induced by hyposmolarity followed that of volume recovery. Efflux of 3H-taurine in an 8 min period was 17.8% (of total labeled taurine accumulated during loading) in an isosmotic medium. Reducing osmolarity to 0.87, 0.75, 0.62, and 0.5 increased this release to 24.8%, 38.1%, 56.4% and 70.9%, respectively. The volume-sensitive release of 3H-taurine was unaffected by omission of external Na+ or Ca++ and was reduced by 23% in the absence of Cl-. It was unaffected by agents disrupting the cytoskeleton or by tetraethylammonium, barium, quinidine, and gadolinium, but was 26% reduced by DIDS. Taurine release was inhibited at 4 degrees C, but was unchanged at 15 degrees C or 25 degrees C. An involvement of FAA, particularly taurine, in lymphocyte volume regulation is suggested.
暴露于低渗介质中的兔淋巴细胞首先会肿胀，然后在6分钟内恢复其初始体积。在体积恢复过程中，游离氨基酸（FAA）从451.1纳摩尔/毫克蛋白质降至208纳摩尔/毫克蛋白质。牛磺酸是主要的FAA，占FAA总量的70%。低渗诱导的3H-牛磺酸释放的时间进程与体积恢复的时间进程一致。在等渗介质中，8分钟内3H-牛磺酸的流出量为（加载过程中积累的总标记牛磺酸的）17.8%。将渗透压分别降至0.87、0.75、0.62和0.5时，这种释放分别增加到24.8%、38.1%、56.4%和70.9%。3H-牛磺酸的体积敏感性释放不受外部Na+或Ca++缺失的影响，在没有Cl-的情况下减少23%。它不受破坏细胞骨架的试剂或四乙铵、钡、奎尼丁和钆的影响，但被DIDS减少26%。牛磺酸释放在4℃时受到抑制，但在15℃或25℃时没有变化。这表明FAA，特别是牛磺酸，参与了淋巴细胞的体积调节。
