Some aspects of phosphorus metabolism in bone marrow. 2. Changes in the content of phosphorus compounds and reducing substances in bone marrow and spleen, caused by ionizing radiation and other factors which depress the function of blood-forming tissue

Abstract

With suitably graded doses of X-rays it was possible to produce a major breakdown of nucleic acid in the bone marrow and spleen of rats, without affecting markedly the content of lipid P. The changes in bone marrow nucleic acid, whether due to irradiation or to admn. of myelotoxic substances such as aminopterin, were accompanied by a decline in the content of ascorbic acid. The general pattern of post-irradiation changes in the spleen conformed qualitatively to that of bone marrow, but quantitatively it was less pronounced. Muscle adenylic and yeast adenylic, but not inosinic acid, appeared to delay the recovery of nucleic acid P and ascorbic acid content in the bone marrow and spleen of irradiated rats. Aminopterin, amethopterin and colchicine selectively affected the bone marrow and had relatively little effect on spleen; mustard sulfoxide, potentiated by dimethyldithiocarbamate, acted like X-rays upon both marrow and spleen. The P distr. in the bone marrow of splenectomized rats was indistinguishable from unoperated controls; the same was true concerning the response of splenectomized rats towards X-rays.