A unitary cause for the exclusion of NA⁺ and other solutes from living cells, suggested by effluxes of NA⁺, D‐arabinose, and sucrose from normal, dying, and dead muscles

Abstract

1. The effluxes of labeled Na+, D-arabinose, and sucrose from normal muscle and muscle poisoned with low concentrations of iodoacetate were studied. The procedure involved repeated loading with isotope, followed by washing of the same muscle while still normal and at different states of dying. 2. The rates of Na+ efflux in both the fast and slow fraction remained either quite constant or showed some unpredictable, minor fluctuations. This was true for both Na+ and the two sugars studied, confirming earlier conclusions that the steady levels of these solutes were not maintained by pumps. 3. In all cases studied, the efflux curves showed at least two fractions. It is the fast-exchanging fraction that steadily and consistently increased in magnitude as the muscles were dying, until finally the concentration of solute in this fraction reached and sometimes surpassed the labeled solute concentrations in the original labeled solutions in which the muscles were equilibrated. The slow fractions showed only a transient increase or none at all. These observations show that it is the fast fraction that represents solute dissolved in cell water and rate-limited by passage through the cell surface and that the partial exclusion of Na+ and the sugars have a unitary cause--a reduced solubility in the cell water which in the presence of ATP exists in the state of polarized multilayers.

Intracellular ethanol — accumulation and exit from yeast and other cells

“…methanol > ethylene glycol > glycerol > xylose, glucose > methylglucoside > sucrose [83]. methanol > ethylene glycol > glycerol > xylose, glucose > methylglucoside > sucrose [83].…”

“…does not behave as free water, and upon death this water reverts to the free state [81][82][83]. Indeed the very living nature of a cell has been shown to structure the water in a unique way which is not observed in dead cells such that some 60% of the cell water in a living cell is 'biostructured', i.e.…”

“…For instance, phosphatidylcholine, a membrane phospholipid binds around 0.3 g non-solvent water/g lipid, i.e. Proteins and other cell biopolymers bind similar large amounts of water [83,[89][90][91][92][93] and in doing so arrange the adjacent water into what is termed polarized multilayers. The solubility of non-electrolytes in this bound water layer is much lower than in pure water [86,87] and the lateral diffusion of water in this layer is 100-times slower than in free water [88].…”

“…5-12 mol water/mol lipid -or the equivalent of two monolayers of water while a further 3-9 mol/mol is less tightly bound, giving a total of 3 monolayers of bound water [84][85][86]. Such multilayers have a highly hydrogen-bond-oriented state resulting in reduced solvent properties [83,[89][90][91][92][93]. Proteins and other cell biopolymers bind similar large amounts of water [83,[89][90][91][92][93] and in doing so arrange the adjacent water into what is termed polarized multilayers.…”

“…Based upon the fact that the D-sugar always showed a higher distribution coefficient than the L-sugar, it was proposed that this distribution was the result of separate membrane enclosed compartments within the cell which accepted only certain kinds of sugars [96][97][98][99]. it is a fundamental and not just a biological effect [83,[90][91][92][93]. The earlier hypothesis is therefore incorrect and the more simpler explanation based on the properties of the cytoplasm is more enlightening.…”