AJP - Cell Physiology, Vol 244, Issue 5 429-C432, Copyright © 1983 by American Physiological Society
Kidney epithelial cell growth is stimulated by lowering extracellular potassium concentration
M. M. Walsh-Reitz and F. G. Toback
The factors that induce kidney growth in K+-depleted animals are unknown.
To determine if the low extracellular fluid K+ concentration could act as a
growth stimulus, cultures of monkey kidney epithelial cells from the BSC-1
line were studied in media with a low-K+ concentration. Growth of confluent
cultures was accelerated maximally at a K+ concentration of 3.2 mM, whereas
concentrations of 2.9 and 3.5 mM were also stimulatory but to a lesser
extent. Because growing renal tissue from K+-depleted rats was previously
found to exhibit increased uptake of nutrient molecules, evidence for
enhanced uptake was sought in BSC-1 cells after exposure to low-K+ medium.
The uptake of 10 different nutrient molecules was enhanced in cells exposed
to low-K+ medium for 30 s. These observations indicate that a reduced
extracellular K+ concentration per se stimulates proliferation of renal
epithelial cells in culture and could be one of the factors that mediate
kidney growth in K+-depleted animals.
