Bone marrow function in perfused isolated hind legs of rats

¹ Department of Biology, Graduate School of Arts and Science, New York University, New York City, and Merck Institute for Therapeutic Research, Rahway, New Jersey

Successful use has been made of a perfusion technique in the study of bone marrow in isolated hind legs of rats. With this method, legs of rats were perfused for a period of 4 hours without showing signs of rigor or edema. Except for a rise in inorganic phosphate in the perfusate, the physiologic, pharmacologic and biochemical aspects of the perfusate and marrow were essentially normal throughout the experimental period. The femoral marrows within isolated legs of rats showed significant increases in the nucleated red blood cell numbers when perfused with whole blood obtained from rats subjected to a) low barometric pressures, b) hemorrhage or c) phenylhydrazine treatment, thus indicating a direct action of the circulating ESF on the blood-forming tissues. Stimulatory effects upon erythropoiesis were also observed in legs of vitamin B₁₂-deficient rats perfused with whole blood and in legs perfused with blood containing aminopterin.