NON-SPECIFIC CHANGES IN THE OPSONIC POWER OF RABBIT SERUM PRODUCED PHYSICALLY THROUGH THE INTRAVASCULAR INJECTION OF FOREIGN PARTICLES IN SUSPENSION

¹ Department of Physiology, McGill University, Montreal, Canada

The intravenous administration of (chemically inert) quartz suspensions causes a physico-chemical alteration in the white-cell plasma relations due to non-specific changes produced physically in the rabbit's blood serum, which results in a profound decrease in the ability of the polymorphs to phagocyte Staphylococcus pyogenes aureus in vitro in the presence of their own serum. If serum from a normal rabbit is substituted, the cells again become able to phagocyte. If cells from a normal rabbit are incubated with the "treated" rabbit's serum, they tend to lose their phagocytic ability.

The phenomenon is due to a lack of some substance, "opsonin," from the serum of the treated animal. This lack can be compensated for by the addition of a normal control serum.

It has been found possible to vary experimentally by a physical method the "opsonic" content of the blood serum of a rabbit without the use of vaccines.

I wish to acknowledge my indebtedness to Professor John Tait for much helpful criticism in preparing this paper for press.