. Electrolytes in biological systems, incorporating papers presented at a symposium at the Marine Biological Laboratory in Woods Hole, Massachusetts, on September 8, 1954 . The kinetics of K+ leakage can be readily characterized if the K+ concentra- tion can be maintained at levels below the steady state concentration, 5 X lo"^ m/1. in this case. Ordinarily, it is difficult to study K+ leakage and uptake at low K+ concentrations because the cells establish the steady state in a few minutes. The problem has been resolved by passing the medium continuously through a column of packed cells a
. Electrolytes in biological systems, incorporating papers presented at a symposium at the Marine Biological Laboratory in Woods Hole, Massachusetts, on September 8, 1954 . The kinetics of K+ leakage can be readily characterized if the K+ concentra- tion can be maintained at levels below the steady state concentration, 5 X lo"^ m/1. in this case. Ordinarily, it is difficult to study K+ leakage and uptake at low K+ concentrations because the cells establish the steady state in a few minutes. The problem has been resolved by passing the medium continuously through a column of packed cells at a rate such that the medium is in contact with the cells for only a short period of time. Samples of the medium are taken continuously by a standard fraction collector and analyzed for ionic content. By this technique K+ leakage or uptake can be studied in a system in which the K+ concentration can be controlled at very low values. At pn , there is a constant leakage of K+ from the cells at a rate of mu/kg of cells each hour. After glucose is added to the system, the rate of leakage increases about four fold to mm/kg hr. (fig. 6). At pH , the rate of leakage is markedly in- creased, 16 mM/kg hr. without substrate, and 46 mM/kg hr. with substrate. At the latter rate, one third of the cellular K+ leaks out in an hour. The de- creased rate of leakage observed after 165 minutes in figure 6 at pn 2 is probably
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Keywords: ., bookcentury1900, booksubjectelectrolytes, booksubjectphysiologyc
