Vásárhelyi B, Reusz G, Sallay P, Tulassay T
I. Gyermekgyógyászati Klinika, Semmelweis Orvostudományi Egyetem, Budapest.
Orv Hetil. 1996 Oct 6;137(40):2193-6.
The enzyme Na+/K(+)-ATPase plays a central role in the regulation of transmembrane ionic transports. According to previous reports its activity decreased in uremic state. The activity of Na+/K(+)-ATPase in detergent pretreated erythrocytes was studied in seven uremic children prior to and following the hemodialysis (HD) session. Additionally, the level of endogenous digoxin like factors in the plasma (EDLF) was determined. Before the HD session the Na+/K(+)-ATPase activity decreased compared to the control value (mean +/- SD: 2078 +/- 527 vs 3245 +/- 362 nmol P/ml RBC/h, p < 0.01). Following HD it became normal (3366 +/- 952 nmol P/ml RBC/h, n.s.). Prior to the HD the EDLF level was higher, while after the HD no difference was noted from the control value (0.29 +/- 0.04, p < 0.05; 0.24 +/- 0.04 n. s. vs control; 0.21 +/- 0.04 ng/ml). Before the HD blood pressure was significantly elevated compared to the control (117 +/- 20/92 +/- 18 vs 95 +/- 2/64 +/- 2 Hgmm, p < 0.05). By the end of the HD it became normal (100 +/- 14/79 +/- 11, n.s.). Although no correlation was found between the EDLF level and Na+/K(+)-ATPase activity, a positive significant correlation was found between the changes of enzyme activity and the changes in the systolic (r = 0.83, p < 0.05) and diastolic (r = 0.82, p < 0.05) blood pressure during the HD. Our results indicate, that in uremic children the Na+/K+ pump is inhibited by a dialysable, blood-pressure regulator substance and so the enzyme activity elevates following the HD session. However, decreased blood pressure activates counterregulatory mechanisms, which-to lower extent-inhibit the activity of the pump.
钠钾-ATP酶在跨膜离子转运的调节中起核心作用。根据先前的报道，其活性在尿毒症状态下会降低。我们研究了7名尿毒症儿童在血液透析（HD）治疗前后经去污剂预处理的红细胞中钠钾-ATP酶的活性。此外，还测定了血浆中内源性洋地黄样因子（EDLF）的水平。在HD治疗前，钠钾-ATP酶活性与对照值相比降低（均值±标准差：2078±527 vs 3245±362 nmol P/ml红细胞/h，p<0.01）。HD治疗后恢复正常（3366±952 nmol P/ml红细胞/h，无统计学意义）。HD治疗前EDLF水平较高，而HD治疗后与对照值无差异（0.29±0.04，p<0.05；0.24±0.04，无统计学意义 vs 对照；0.21±0.04 ng/ml）。HD治疗前血压与对照相比显著升高（117±20/92±18 vs 95±2/64±2 mmHg，p<0.05）。HD治疗结束时恢复正常（100±14/79±11，无统计学意义）。虽然未发现EDLF水平与钠钾-ATP酶活性之间存在相关性，但发现HD治疗期间酶活性变化与收缩压（r = 0.83，p<0.05）和舒张压（r = 0.82，p<0.05）变化之间存在显著正相关。我们的结果表明，在尿毒症儿童中，钠钾泵受到一种可透析的血压调节物质的抑制，因此HD治疗后酶活性升高。然而，血压降低会激活反调节机制，该机制在较小程度上抑制泵的活性。
