Isotonicity of liver and of kidney tissue in solutions of electrolytes.

Solutions of a wide variety of electrolytes, isotonic with liver or with kidney tissue, have approximately the same osmotic pressure as solutions of sodium chloride isotonic with tissues of the two organs respectively; that is, with solutions approximately twice as concentrated as the sodium chloride of mammalian blood plasma. The molar concentration of various electrolytes isotonic with liver or with kidney tissue immediately after its removal from the body is determined by the molecular weight, valency, and ion-dissociation of these electrolytes in accordance with the well known conditions of osmosis. The plasma membranes of liver and of kidney cells are imperfectly semipermeable to electrolytes, and those that enter the cell, though retarded in so doing, bring about injury which increases permeability to water. The osmotic activity of cells of mammalian liver and kidney immediately after their removal from the body resembles that of plant cells, egg cells of marine invertebrates, and mammalian red blood corpuscles and presumably represents a basic property of living cells by which osmotic pressure may be adjusted to functional need.