Effect of ammonium chloride on osmotic behavior

Ammonium chloride, demonstrated to be a permeating electrolyte for human red cells in water or sodium chloride solutions, has been shown to act as if it contributes osmotic support in the presence of sucrose. The additional protection provided by ammonium chloride against hemolysis in hypotonic sucrose was found to approximate the milliosmolar concentration of the added salt. In view of previous suggestions that potassium loss was responsible for the increased protection observed with hypotonic nonelectrolyte alone, it was considered reasonable that the further protection afforded by ammonium chloride might reflect a comparable mechanism.