Phagocytosis of Red Blood-Cells Treated by Tannin.

Abstract

Northrop and Freund 1 found that red blood-cells of sheep suspended in dextrose solution are agglutinated by electrolysis whenever the potential is depressed to 6 millivolts or less, except in the case of Mg Cl₂ and Ca Cl₂. When, however, cells are sensitized by specific antibody, ricin, 2 collodial stannic hydroxide, 3 an emulsion of paraffin oil, 1 they are agglutinated below about 12 millivolts, that is, at a potential higher than the critical potential for agglutination of unsensitized cells. This observation constitutes evidence that from the physical-chemical point of view specific antibody mediates agglutination by the same mechanism as ricin, collodial stannic hydroxide solution, and paraffin oil.

Recently Reiner and Fischer 4 have been able to show that another substance, tannin (carefully neutralized), causes agglutination of red blood-cells of sheep, ox, and guinea pig and that red blood-cells treated with tannin become hemolyzed in the presence of guinea pig complement.

Repeating and extending Reiner's and Fischer's work I have found that erythrocytes of sheep exposed to 0.4 and 0.1 pro mille tannin solution, after they have been washed by centrifugalisation, are hemolyzed by the addition of guinea pig complement. If the mechanism of the action of tannin upon erythrocytes is similar to the action of immune serum, in which the electrical charge of the cells plays a rôle, agglutination and hemolysis should not occur when the suspending medium is free from electrolytes. When the experiment was repeated using isotonic dextrose instead of saline solution, neither agglutination nor lysis occurred. When tannin was added to red blood cells suspended in salt solution, the cells became agglutinated, but when the tubes were centrifugalized and the supernatant fluid replaced with dextrose solution, the cells could be suspended evenly and the addition of complement failed to cause lysis.