ABSTRACT
Stroma-free methemoglobin solutions were prepared from dog and pig red blood cells. The procedure is based on oxidizing the ferrous iron in hemoglobin solution to the ferric state. Then all the cell membrane components (i.e.stroma) were removed through crystallization of the hemoglobin molecule in high ionic phosphate buffer, dialysis and repeated washing of crystals prior to solubilization. This method is feasible and reproducible. The methemoglobin solution obtained had similar potassium, sodium, chloride ion concentration and pH value as normol serum. Spectral maxima and minima were characteristic for methemoglobin.SFMS proved to be an effective antidote for cyanide intoxication. Its protection ratio was calculated to be 2.25 while the rats were treated with SFMS equal to 7 % of their total body hemoglobin. The potential advantages of SFMS over current antidotes include its immediate action with cyanide and doesn't compromise any of the patient's oxygen carrying capacity. In preliminary work, SFMS was given at levels of 4-10% total hemoglobin with little adverse effects.