. Electrolytes in biological systems, incorporating papers presented at a symposium at the Marine Biological Laboratory in Woods Hole, Massachusetts, on September 8, 1954. Electrophysiology; Electrolytes; Electrolytes; Electrophysiology; Physiology, Comparative. 58 ELECTROLYTES IN BIOLOGICAL SYSTEMS enough to account for the observed ratio of internal to external potassium and the Donnan principle cannot apply (28). Influence of Cold on Ulva and Valonia. One of the first suggestions that there was a close association of metabolism with cation regulation was made by Harris (16) on observing a r
. Electrolytes in biological systems, incorporating papers presented at a symposium at the Marine Biological Laboratory in Woods Hole, Massachusetts, on September 8, 1954. Electrophysiology; Electrolytes; Electrolytes; Electrophysiology; Physiology, Comparative. 58 ELECTROLYTES IN BIOLOGICAL SYSTEMS enough to account for the observed ratio of internal to external potassium and the Donnan principle cannot apply (28). Influence of Cold on Ulva and Valonia. One of the first suggestions that there was a close association of metabolism with cation regulation was made by Harris (16) on observing a reaccumulation of potassium by human erythrocytes after the cells had been kept in the cold and were then returned to 38°C. A study of the Qio for potassium exchange by Ponder (31), Sheppard and Martin (41) and Raker et al. (32) further supported the idea of a direct influence of carbohydrate metabolism on electrolyte balance. TRANSFERRED TO RUNNING SEA WATER. 0 50 100 150 200 250 300 350 400 HOURS Fig. 17. Loss of potassium and gain of sodium in Valonia macropliysa resulting from m/1. phenyl urethane. At the time indicated by the arrow the cells were transferred to running sea water without the inhibitor. Attempts to demonstrate an influence of temperature on sodium and potas- sium balance in Ulva have not been too successful since these cations in Ulva undergo no significant change when the alga is maintained at 2°C for 24 hours. It is possible that mechanisms operate to reduce the permeability of the cells to cations so that even though the rate of metabolism (and likewise transport mechanisms) is reduced, the cell maintains its normal composition at least for 24 hours. In the case of Valonia, however, when the cells are maintained at 2 to 5°C for approximately 75 hours, a slight loss of potassium and gain of sodium occurs. On return to a temperature of i8°C a further and striking loss of potassium and gain of sodium takes place. After 75 hours at the higher tempera
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