Fundamental Studies on the Transport of Substances Across Biological Membranes-V

Transport of Water Across Lecithin-Membrane

Abstract

Previously^{1, 2)}, the authors studied on the transport of water through cephalin-membrane, and presumed that the membrane had characteristic of negatively charged membrane from the presence of an anomalous osmosis in electrolyte solution which occurred across the membrane from the side of water to the side of electrolyte solution. In the present paper, the transport of water through lecithin-membrane at different concentrations of salts and acids was examined. The results were as follows:
In the salt solutions, it was shown that the transport was similar to that of cephalin-membrane¹⁾, but positive osmosis was relatively lower than that of cephalin-membrane (Fig. 1, 3).
In the acidic solution, e. g. hydrochloric acid, sulfuric acid and L-glutamic acid, the transport decreased with increasing concentration of the solution, and their curves showed neither maximum nor minimum point in the region from M/1024 to M/2. The transport was of positive osmosis in a low concentration region, and was of negative osmosis in a high concentration region (Fig. 2).
In the solution of acetic acid or glycine, the transport did not vary for all concentration in this experiment (Fig. 2).
It is possible to conclude that the lecithin-membrane has a property of negatively charged membrane in the neutral solution, but has that of a positively charged membrane in the acidic solution.