Further Studies with Cell-Free Extracts from Mouse Spleen on X-Ray Induced Mortality.

Abstract

The effect of spleen extracts of normal and irradiated mice on X-ray induced mortality of mice was studied. Spleens were quick-frozen in dry ice, extracted at refrigerator temperature with saline and made cell-free by centrifugation and bacterial filters. Extracts made from the spleens of unirradiated donor animals showed definite protective effect while spleenic extracts of animals exposed to an X-ray dose which killed 55% of the donor animals in 14 days failed to show protection, in agreement with previous observations. A parallelism between the protective effect of various extracts made from normal mouse spleens and the failure to protect of those made from irradiated mouse spleens was found in studies of the total protein and NPN content of such extracts. It appears that within a wide range of concentration of total protein and NPN content such protection can be achieved.