有家族史的高血压病患者细胞膜离子转运改变及意义

Changes of transmembrane ion transport in essential hypertensives with familial histories

目的 探讨高血压病中遗传因素对细胞膜离子转运的影响。方法 分为有家族史（ＦＨ＋） 高血压组２３ 例和无家族史（ＦＨ－） 高血压组２９ 例，２５ 例健康人作对照组。红细胞４５Ｃａ２＋ 内流用液态闪烁计数器测定，细胞内Ｎａ＋ 浓度（［Ｎａ＋］ｉ）和红细胞哇巴因敏感钠外流速度常数（ｏＫｏｓ） 用火焰光度法测定；测定不同外向Ｈ＋ 浓度梯度时的Ｎａ＋ 内流，计算出Ｎａ＋ ／Ｈ＋ 交换最大速率Ｖｍａｘ。结果 ＦＨ＋ 和ＦＨ－ 高血压病组红细胞Ｎａ＋ ／Ｈ＋ Ｖｍａｘ 交换和４５Ｃａ２＋ 内流均高于对照组，Ｎａ＋ 泵活性低于对照组；ＦＨ＋ 高血压病患者Ｎａ＋ 泵活性高于ＦＨ－ 高血压病组，但４５Ｃａ２ ＋ 内流较低。在ＦＨ＋ 高血压病患者中，收缩压与年龄呈正相关，舒张压与红细胞４５Ｃａ＋ 内流呈正相关。结论 高血压病遗传因素可导致Ｃａ２＋ 转运异常，细胞膜对Ｃａ２＋ 被动通透性增加及胞内可交换游离Ｃａ２＋ 池扩大参与遗传性高血压的发病机制。

Objective To investigate the effects of heredity on transmembrane ion transport in essential hypertension (EH). Methods 52 essential hypertensives were divided into two groups, 23 with positive family history (FH +) and 29 with negative family history (FH -). The rate constant of ouabain sensitive sodium efflux ( oK os ) was measured as the half of the increase in erythrocyte Na + concentration during incubation with ouabain for 2 hours, oK os was calculated by an equation and the maximal rate (Vmax) of red cells Na +/H + exchange was determined as the Na + influx promoted by an outward H + gradient. Intracellular Na + concentration was measured with flame photometry and 45 Ca 2+ influx in ATP depleted red cells with liquid scintillation counting. Results The red cell Na +/H + exchange and 45 Ca 2+ in flux were significantly higher but the oK os lower in both the FH + and FH - groups than in the controls. FH + group demonstrated a significantly higher oK os and lower Ca 2+ influx as compared with those in FH - group. In FH + group, systolic blood pressure was positively correlated with age, while diastolic blood pressure positively correlated with 45 Ca 2+ influx. Conclusion Our data show a genetic contribution to abnormal membrane transport in hypertension. There is a defect in membrane permeability to Ca 2+ and a greater exchangeable pool of cytosolic free Ca 2+ in FH + group that participate in the pathogenesis of inherited hypertension.