STUDIES UPON THE EFFECT OF LIGHT ON BLOOD AND TISSUE CELLS

Abstract

1. It was found that when hanging drops of whole blood, drawn from a rabbit, were subjected to irradiation from certain light sources, a striking degeneration of the white and of the red cells occurred. In this degeneration of the red cells there was (a) a preliminary period of 15–30 minutes during which no effect was noted; (b) following this, there was a period during which the cells swelled and became first almost biplanar, then biconvex, and finally spherical. After a spherical shape had been assumed, the liberation of blood pigment from the cells began. This process progressed with varied rapidity, sometimes being very slow, and being incomplete; sometimes being of almost explosive rapidity. This liberation was not accomplished in either case through a gross rupture of the cells, but through the agency of some submicroscopic change produced either in the cell contents, the cell wall, or both. Following this liberation of pigment, in some cultures the red cells showed signs of coagulation, as did the white cells. In other cultures, however, the red cells were reduced to achromatic shadows. 2. When whole blood was diluted with unbuffered Locke solution and then irradiated in hanging drop preparations, the erythrocytes swelled, as in whole blood, but then, instead of an almost instantaneous hemolysis of every cell present, or a slow liberation of hemoglobin from each individual cell, all the red cells hemolyzed, one or two at a time, the hemolyzed cells being left as achromatic shadows. 3. This hemolysis of the red cells, as in the case of the degeneration of the white cells, occurred upon irradiation of the culture with white light, or with light lying in each of the three spectral zones of the visual spectrum, defined by Wratten filters Nos. 45, 58 and 29 respectively, as follows: (a) 430µµ–550µµ; infra-red; (b) 475µµ–630µµ; 690µµ-infra-red; (c) 600µµ-infra-red. 4. Within the range of intensities of light employed, there was little or no difference in the rate at which light of these three regions acted on the red cells. Further, this rate was the same as was the rate when the red cells were irradiated with no colored filter interposed in the optical path, or when a 5 per cent total transmission neutral filter was interposed. 5. It was shown that this degeneration of the red cells under the action of light was not dependent on the presence or absence of serum, with the possible exception of that trace which might have been adherent to the red cells even after repeated washing. 6. The white cells in the culture generally showed no changes until after traces of red cell pigment could be seen free in the surrounding medium. 7. On the other hand, no neutrophils were observed moving around for longer than a few minutes after the liberation of red cell pigment had occurred. 8. The liberation of substances from the red blood cells, as a result of irradiation of such preparations, may play some major rôle in the degeneration of irradiated white cells.