The Effect of Type III Pneumococcus Polysaccharide and Gelatin on the Circulation and Sedimentation Rate of Erythrocytes in Mice

Abstract

Intraven. injn. of Type III pneumococcus polysaccharide or iso-electric gelatin solns. into anesthetized mice produced the following results: 1) Slowing and irregularity of blood cell flow could be seen by observing the small blood vessels of the mesentery microscopically. This was due to the intravascular clumping of the red blood cells. 2) Increases in the sedimentation rate. In the case of the polysaccharide, return to normal of the increased rate roughly corresponded to the disappearance of the circulatory alterations produced by this substance. In considering the possible significance of these results to an understanding of the pathogenesis of pneumococcus pneumonia, the authors state that a continuous outpouring of pneumococcus polysaccharide into the blood stream of an infected patient, resulting in intravascular aggregation of the red blood cells, could interfere with the dynamics of the blood flow and the normal exchange of respiratory substances between the blood and tissues. This chain of events may be responsible, at least in part, for the circulatory difficulties which are common in this disease.