INTRACELLULAR PH IN RAT RESISTANCE ARTERIES DURING THE DEVELOPMENT OF EXPERIMENTAL-HYPERTENSION
INTRACELLULAR PH IN RAT RESISTANCE ARTERIES DURING THE DEVELOPMENT OF EXPERIMENTAL-HYPERTENSION
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DOI：
10.1042/cs0810065
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发表时间：
1991-07-01
期刊：
影响因子：
6
通讯作者：
HEAGERTY, AM
中科院分区：
文献类型：
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作者：
IZZARD, AS;MACIVER, DH;HEAGERTY, AM
1.为探讨实验性高血压对肠系膜阻力动脉细胞内pH的影响，在大鼠主动脉部分缩窄肾动脉起点后72小时、9天和28天测定肠系膜阻力动脉的细胞内pH。结论：1.颈动脉压在各时间点均明显升高。二级肠系膜阻力动脉被安装在肌图仪上，并被pH敏感染料2‘，7’-bis(carboxyethyl)-5，6-carboxyfluorescein.的乙酰氧甲酯负载形态学测量显示，与假手术对照组相比，缩窄大鼠动脉在第9天和第28天的中膜体积增加，但这仅在第28天有统计学意义。动脉缩窄后各时间点静息细胞内pH与对照组相比无显著差异，但在72~9d两组大鼠动脉内pH均有升高。应用4，4-di-isothiocyanatostilbene-2，2‘-disulphonic酸后，假手术组大鼠细胞内pH在第9天下降更明显，第28天则无明显差异。用60mU-mol/L乙基异丙基阿米洛利阻断Na~+/H~+交换，9天时两组大鼠动脉细胞内pH下降相似，28天时缩窄大鼠动脉细胞内pH下降更明显。去甲肾上腺素(10-mU/L)激活可引起两组大鼠细胞内pH的酸性变化，两组大鼠的变化相似。结果表明，主动脉缩窄的诱导与肠系膜阻力动脉的显著生长有关，但这种结构变化与细胞内pH无关，而细胞内pH在任何时候都与假手术对照组大鼠显著不同。Na+/H+交换对细胞内pH的调节作用仅在中等生长后28天观察到，这与这种交换系统作为细胞生长中介的基本作用是相反的。
1. In order to examine the effects of experimental hypertension on intracellular pH in mesenteric resistance arteries, intracellular pH was measured in mesenteric resistance arteries from rats with coarctation 72 h, 9 days and 28 days after the aorta was partially constricted between the origins of the renal arteries. Carotid arterial pressure was significantly raised at all time points.2. Second-order mesenteric resistance arteries were mounted in a myograph and were loaded with the acetoxymethyl ester of the pH-sensitive dye 2',7'-bis(carboxyethyl)-5,6-carboxyfluorescein. Morphological measurements demonstrated that arteries from rats with coarctation had an increased media volume at 9 days and at 28 days compared with vessels from sham-operated control animals, but this was only statistically significant at 28 days.3. Resting intracellular pH was not significantly different at any time point in arteries from rats with coarctation compared with control animals, although there was a rise in intracellular pH in both groups of rats between 72 h and 9 days. The application of 4,4-di-isothiocyanatostilbene-2,2'-disulphonic acid produced a fall in intracellular pH which was significantly greater in the sham-operated rats at 9 days; this difference was not found at 28 days. Blockade of Na+/H+ exchange with 60-mu-mol/l ethylisopropylamiloride led to a similar fall in intracellular pH in both groups of rats at 9 days but a significantly greater fall in intracellular pH in arteries of rats with coarctation at 28 days. Activation with noradrenaline (10-mu-mol/l) induced acid changes in intracellular pH that were similar in both groups of rats.4. It is concluded that induction of coarctation of the aorta was associated with the development of significant growth in mesenteric resistance arteries, but that this structural change was not associated with an intracellular pH that was significantly different from that seen in sham-operated control rats at any time. Increased regulation of intracellular pH by Na+/H+ exchange was observed only at 28 days, after medial growth had occurred, which argues against a fundamental role of this exchange system as a mediator of cell growth.