自发性高血压大鼠培养的骨骼肌细胞和血管平滑肌细胞中钠/氢逆向转运活性改变的证据。

Evidence for altered Na+/H+ antiport activity in cultured skeletal muscle cells and vascular smooth muscle cells from the spontaneously hypertensive rat.

Davies J E, Ng L L, Ameen M, Syme P D, Aronson J K

Sheikh Rashid Diabetes Unit, Radcliffe Infirmary, Oxford, U.K.

Clin Sci (Lond). 1991 May;80(5):509-16. doi: 10.1042/cs0800509.

Abstract

Intracellular pH and Na+/H+ antiport activity were determined by a fluorimetric method in cultured skeletal muscle cells (myoblasts) and aortic vascular smooth muscle cells from spontaneously hypertensive and normotensive Wistar-Kyoto rats. 2. The intracellular pH was significantly more alkaline at three different extracellular pH values in both myoblasts and vascular smooth muscle cells from the spontaneously hypertensive rats than in those from the normotensive control rats. 3. A kinetic analysis of the Na+/H+ antiport activity in these cells showed that the raised activity in the spontaneously hypertensive rats was due to an increased maximal transport capacity in vascular smooth muscle cells and to an increase in the affinity of the antiport for internal H+ in the myoblasts. 4. When the extracellular pH was reduced in the skeletal muscle cells of both types of rat, the intracellular pH fell. However, in vascular smooth muscle cells, a reduction in the extracellular pH was not associated with a fall in the intracellular pH. This resistance of the intracellular pH to changes in the extracellular pH differentiates vascular smooth muscle cells from other cells that have been studied in this way.

摘要

采用荧光法测定了自发性高血压和正常血压的Wistar - Kyoto大鼠的培养骨骼肌细胞（成肌细胞）和主动脉血管平滑肌细胞内的pH值以及Na⁺/H⁺逆向转运活性。2. 在三种不同的细胞外pH值条件下，自发性高血压大鼠的成肌细胞和血管平滑肌细胞内的pH值均显著高于正常血压对照大鼠的相应细胞。3. 对这些细胞中Na⁺/H⁺逆向转运活性的动力学分析表明，自发性高血压大鼠中该活性的升高是由于血管平滑肌细胞的最大转运能力增加以及成肌细胞中逆向转运体对细胞内H⁺的亲和力增加所致。4. 当降低两种大鼠骨骼肌细胞的细胞外pH值时，细胞内pH值下降。然而，在血管平滑肌细胞中，细胞外pH值的降低并未伴随着细胞内pH值的下降。细胞内pH值对细胞外pH值变化的这种抗性使血管平滑肌细胞有别于以这种方式研究过的其他细胞。