Objective: To investigate the role of heredity in the ouabain-resistant phenomenon and the rela tionship between ouabain-resistance and transmembrane ion transport in essential hypertensives. Methods:A total of 52 ess...Objective: To investigate the role of heredity in the ouabain-resistant phenomenon and the rela tionship between ouabain-resistance and transmembrane ion transport in essential hypertensives. Methods:A total of 52 essential hypertensives were investigated. of the patients, 23 were with a family history of hyper tension (FH+ group) and 29 were without (FH- group). Other 25 normotensives were employed to serve as the controls (control group). The percentage of 125I-digoxin binding to red blood cells (RBC-D% ) and plasma endogenous digoxin-like substance (EDLS) were measured with radioimmunoassay, 45Ca2+ influx in ATP-de pleted red cells by liquid scintillation counting. The rate constant of ouabain-sensitive sodium efflux (°Kos, h-1) was analyzed as half the increase in erythrocyte Na+ concentration during incubation with ouabain for 2 h. The maximal rate (Vmax) of red cell Na+/H+ exchange was determined as the influx promoted by an out ward H+ gradient then calculated. Results:The ouabain-sensitive Na+ efflux and RBC-D% were significantly lower but the levels of plasma EDLS and 45Ca2+ influx significantly higher in both FH+ and FH groups than in the control group. The plasma EDLS and ouabain-sensitive Na+ efflux were significantly higher but Ca2+ innux lower in FH+ group than in FH- group. Positive correlation was found between RBc-D% and ca2+ in flux in FH+ group. Conclusion: Ouabain-resistant phenomenon is related to the heredity of hypertension.The decrease in affinity of EDLS for membrane affects the transmembrane ion transport, which may partici pate in the pathogenesis of salt-sensitive hypertension.展开更多
The transport of sodium ions by erythrocytes and the plasma level of endogenous digitalis-like compound (EDLC) were assessed in 59 patients with essential hypertension before and after theadminstration of nifedipine a...The transport of sodium ions by erythrocytes and the plasma level of endogenous digitalis-like compound (EDLC) were assessed in 59 patients with essential hypertension before and after theadminstration of nifedipine and prazosin. 20 normal subjects were studied similarly and served as con-trol. It was found that (1) EH patients had a pronounced defect of both the active and passive trans-port of sodium ions by the erythrocytes; (2) a higher plasma level of EDLC was detected in EH pa-tients as compared with that of the control, but the changes of EDLC and soudium pump were notparallel; (3) after the administration of nifedipine and prazosin, the function of sodium pump wasmarkedly improved and the plasma level of EDLC decreased. In addition, the relationship betweenthe transport of sodium ions by erythrocytes and the pathogenesis of EH, and the effects of anti-hypertensive agents were discussed.展开更多
文摘Objective: To investigate the role of heredity in the ouabain-resistant phenomenon and the rela tionship between ouabain-resistance and transmembrane ion transport in essential hypertensives. Methods:A total of 52 essential hypertensives were investigated. of the patients, 23 were with a family history of hyper tension (FH+ group) and 29 were without (FH- group). Other 25 normotensives were employed to serve as the controls (control group). The percentage of 125I-digoxin binding to red blood cells (RBC-D% ) and plasma endogenous digoxin-like substance (EDLS) were measured with radioimmunoassay, 45Ca2+ influx in ATP-de pleted red cells by liquid scintillation counting. The rate constant of ouabain-sensitive sodium efflux (°Kos, h-1) was analyzed as half the increase in erythrocyte Na+ concentration during incubation with ouabain for 2 h. The maximal rate (Vmax) of red cell Na+/H+ exchange was determined as the influx promoted by an out ward H+ gradient then calculated. Results:The ouabain-sensitive Na+ efflux and RBC-D% were significantly lower but the levels of plasma EDLS and 45Ca2+ influx significantly higher in both FH+ and FH groups than in the control group. The plasma EDLS and ouabain-sensitive Na+ efflux were significantly higher but Ca2+ innux lower in FH+ group than in FH- group. Positive correlation was found between RBc-D% and ca2+ in flux in FH+ group. Conclusion: Ouabain-resistant phenomenon is related to the heredity of hypertension.The decrease in affinity of EDLS for membrane affects the transmembrane ion transport, which may partici pate in the pathogenesis of salt-sensitive hypertension.
文摘The transport of sodium ions by erythrocytes and the plasma level of endogenous digitalis-like compound (EDLC) were assessed in 59 patients with essential hypertension before and after theadminstration of nifedipine and prazosin. 20 normal subjects were studied similarly and served as con-trol. It was found that (1) EH patients had a pronounced defect of both the active and passive trans-port of sodium ions by the erythrocytes; (2) a higher plasma level of EDLC was detected in EH pa-tients as compared with that of the control, but the changes of EDLC and soudium pump were notparallel; (3) after the administration of nifedipine and prazosin, the function of sodium pump wasmarkedly improved and the plasma level of EDLC decreased. In addition, the relationship betweenthe transport of sodium ions by erythrocytes and the pathogenesis of EH, and the effects of anti-hypertensive agents were discussed.