Na+/H+ exchange in patients with mild chronic renal failure.
Cytosolic pH (pHi) and Na+/H+ exchange activity were measured in lymphocytes from 22 patients with mild chronic renal failure, and 21 age- and sex-matched normotensive healthy control subjects using the fluorescent dye technique. The basal pHi in resting lymphocytes was not significantly different in both groups tested (control, pHi 7.18 +/- 0.04; patients with mild chronic renal failure, 7.17 +/- 0.05). The initial rate of pHi recovery immediately after intracellular acidification with 100 mmol/l propionic acid, representing the maximum Na+/H+ exchange activity, was significantly higher in lymphocytes from patients with mild chronic renal failure (7.10 +/- 0.52 dpHi/s, mean +/- SEM) when compared with control subjects (5.42 +/- 0.47 dpHi/s; p < 0.05). No significant correlation between Na+/H+ exchange activity and blood pressure could be obtained in patients with mild chronic renal failure. Furthermore, there was no relationship of Na+/H+ exchange activity to cytosolic pH or extracellular pH. It is concluded that an enhanced Na+/H+ exchange activity can be detected in patients with mild chronic renal failure and may not be related to the significant abnormalities of electrolyte and acid-base metabolism commonly observed in patients with end-stage renal failure or on hemodialysis.
Tepel
M
M
Medizinische Universitäts-Poliklinik, University of Münster, Germany.
Laukemper
S
S
Zidek
W
W
D000136:Acid-Base Equilibrium; D000138:Acidosis / Q000503:physiopathology; D000328:Adult; D001639:Bicarbonates / Q000097:blood; D001794:Blood Pressure; D005260:Female; D005452:Fluoresceins; D005456:Fluorescent Dyes; D006801:Humans; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D007676:Kidney Failure, Chronic / Q000378:metabolism*; D007677:Kidney Function Tests; D008214:Lymphocytes / Q000737:chemistry / Q000201:enzymology / Q000502:physiology; D008297:Male; D008875:Middle Aged; D011422:Propionates / Q000494:pharmacology; D017923:Sodium-Hydrogen Exchangers / Q000378:metabolism*
D001639:Bicarbonates; D005452:Fluoresceins; D005456:Fluorescent Dyes; D011422:Propionates; D017923:Sodium-Hydrogen Exchangers; C043829:2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein; C029658:propionic acid