Cmd. Helou et al., EFFECT OF LOW AND HIGH POTASSIUM DIETS ON H-K+-ATPASE AND NA+-K+-ATPASE ACTIVITIES IN THE RAT INNER MEDULLARY COLLECTING DUCT CELLS(), Renal physiology and biochemistry, 17(1), 1994, pp. 21-26
This study was designed to measure H-K-ATPase and Na-K-ATPase activiti
es in rat inner medullary collecting duct (IMCD) cells during potassiu
m depletion and loading. Both enzyme activities were similarly distrib
uted from the proximal to the distal portion of this nephron segment.
One week K depletion did not stimulate H-K-ATPase activity but reduced
Na-K-ATPase activity. Within 2 weeks after the onset of potassium dep
letion, the rats developed metabolic alkalosis, and H-K-ATPase activit
y was suppressed while Na-K-ATPase activity had returned to control va
lues. H-K-ATPase activity was suppressed following potassium loading w
hereas Na-K-ATPase activity was unchanged. The results are consistent
with the presence of H-K-ATPase in IMCD and indicate that H-K-ATPase a
nd Na-K-ATPase activities are modulated by potassium intake.