Increased lymphocytic Na+/H+ exchange activity after hemodialysis: evidence for an endogenous inhibitor of Na+/H+ exchange in patients with end-stage renal failure.
The Na+/H+ exchange antiport activity was measured in lymphocytes from 16 patients with end-stage renal failure pre- and postdialysis. In addition the effect of the patients' plasma on lymphocytes from healthy subjects was tested. Resting pH (pHi) was not significantly different in lymphocytes pre- and postdialysis. On the other hand, the Na+/H+ exchange activity was significantly lower in lymphocytes before hemodialysis (6.22 +/- 0.73 x 10(-3) pHi/s) than after hemodialysis (9.32 +/- 1.58 x 10(-3) pHi/s; n = 16; p < 0.05). The buffer capacity was not significantly different before and after hemodialysis. The incubation of lymphocytes from healthy control subjects with plasma from patients with end-stage chronic renal failure significantly reduced the lymphocytic Na+/H+ exchange activity. The addition of ultrafiltrate also significantly reduced the Na+/H+ exchange activity in lymphocytes from healthy control subjects. The study indicates the existence of an endogenous inhibitor of the Na+/H+ exchange that is accumulated in plasma from patients with end-stage chronic renal failure.
Universitätsklinik Marienhospital, Ruhr-Universität-Bochum, Herne, Germany.
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Tepel
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Klaus
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Laukemper
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Schlüter
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Zidek
D000328:Adult; D005260:Female; D005452:Fluoresceins; D005456:Fluorescent Dyes; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000628:therapy; D008214:Lymphocytes / Q000378:metabolism*; D008297:Male; D017582:Renal Replacement Therapy; D017923:Sodium-Hydrogen Exchangers / Q000378:metabolism*
D005452:Fluoresceins; D005456:Fluorescent Dyes; D017923:Sodium-Hydrogen Exchangers; C043829:2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein