Mechanism of alteration of sodium potassium pump of erythrocytes from patients with chronic renal failure.

Abstract

substantial increase in cell Na, K pump influx was not higher in uremic erythrocytes with high cell Na. When intracellular Na was altered with nystatin (cell Na equal to 120 mmol/liter cell water in both groups), K pump influx was proportional to the number of Na-K pump sites so that the ion turnover rate per pump site was similar in the two groups. Uremic plasma failed to depress K pump influx of normal erythrocytes. The passive net influx of Na in uremic cells with high intracellular Na was not different from that observed in erythrocytes from normal subjects. When erythrocytes were separated by age on Percoll density gradients, the number of Na-K pump sites of the youngest uremic Preliminary reports of this work were presented at

Volume-sensitive K transport in human erythrocytes.

“…The hemoglobin, hematocrit, and intracellular Na, K, and water contents were measured as described before (Kaji et al ., 1981 ;Cheng et al ., 1984 ; Kaji and Kahn, 1985) . The relative cell volume (RCV) was measured by monitoring the alteration of the mean corpuscular hemoglobin concentration, as described previously (Cheng et al ., 1984).…”

“…The relative cell volume (RCV) was measured by monitoring the alteration of the mean corpuscular hemoglobin concentration, as described previously (Cheng et al ., 1984). The volume of cells in fresh blood was taken as unity.…”

“…Unidirectional K influx was measured by using "Rb as a tracer as described previously (Kaji et al ., 1981 ;Cheng et al, 1984;Kaji and Kahn, 1985) . Packed erythrocytes were suspended at 5% hematocrit in media with various compositions as described in the figure legends.…”

Sustained Voluntary Climbing Exercise Increases Erythrocyte Monocarboxylate Transporter 1 in Rats

“…Thus, the synthesis and membrane incorporation of MCTI protein in erythrocyte are induced during erythropoiesis in the bone marrow. Previous studies described that erythrocyte membrane protein content such as glucose transporter 1 [18] and sodium-potassium pump [17,19] is regulated by environmental changes in plasma, maybe interstitial glucose or intracellular sodium, and the regulation is occurred during erythropoiesis. Erythrocyte MCT 1 would also be already increased at the pre-erythrocyte stage of erythroid cell.…”

Abnormal cation transport in uremia. Mechanisms in adipocytes and skeletal muscle from uremic rats.

“…The accessibility of the erythrocyte has made it an obvious choice for studying ion transport in humans. However, it is unclear whether depressed erythrocyte sodium pump activity in uremia results from fewer functionally active NaK-ATPase enzyme units, from a change in the rate of ion pumping (turnover rate) of each enzyme, or both (1)(2)(3)(4)(5)(6). It is also unclear whether the defect in active cation transport can be acquired by normal erythrocytes upon exposure to uremic sera (7,8).…”