By GEORGE M. GUEST, M.D. V ARIOUS investigators have postulated two main principles which seem to govern the swelling and hemolysis of red blood cells suspended in hypotonic salt solutions: namely, the cells imbibe water according to the laws of osmosis, and their maximum swelling is limited by an inelastic surface membrane. According to this concept, hemolysis occurs when the erythrocytes in h...

The physical properties of fish liver and rat liver mitochondria were compared as a function of temperature and osmotic pressure. The data indicate that fish mitochondria are more flexible and swell at a more rapid rate over a 0 to 30 degrees C temperature range, whereas the rates of swelling at 30 to 40 degrees C are comparable. The swelling rates of both fish and rat mitochondria vary with te...

The expansion of the plasma membrane, which occurs during osmotic swelling of epithelia, must be retrieved for volume recovery, but the mechanisms are unknown. Here we have identified myosin light chain kinase (MLCK) as a regulator of membrane internalization in response to osmotic swelling in a model liver cell line. On hypotonic exposure, we found that there was time-dependent phosphorylation...

The permeability properties of the inner membrane of mung bean mitochondria were studied by osmotic swelling techniques. Rapid mitochondrial swelling was observed in isotonic ammonium phosphate, which indicated that an active phosphate/hydroxyl antiporter was present. The phosphate carrier was specifically inhibited by sulfhydryl reagents. Mitochondria did not swell in isotonic ammonium salts o...

Caveolae have been implicated in sensing of cell volume perturbations, yet evidence is still limited and findings contradictory. Here, we investigated the possible role of caveolae in cell volume regulation and volume sensitive signaling in an adipocyte system with high (3T3-L1 adipocytes); intermediate (3T3-L1 pre-adipocytes); and low (cholesterol-depleted 3T3-L1 pre-adipocytes) caveolae level...

Rat lenses incubated in hypotonic medium adapted to the medium by first undergoing osmotic swelling and then returning after 1 to 2 days to their originial volume. Two processes--osmotic swelling and volume regulation--appear to be working simultaneously. The former is indicated by a decrease in the concentration of cell potassium to the expected level and the latter by a limitation of lens vol...

The swelling of polyelectrolyte (PE) gels by 1:1 and 2:1 salts is studied via osmotic ensemble Monte Carlo simulations at constant osmotic pressure and electrolyte chemical potential of a reservoir phase in equilibrium with a model PE network. Large molecular weight gels exhibit a remarkable swelling response to small changes in 2:1 salt concentration. Gel collapse is accompanied by the formati...