Abstract
1. Four beagles were exposed to supralethal total-body irradiation from a 250 kv x-ray therapy machine. Four were exposed to similar irradiation from a Cobalt-60 teletherapy unit. Dosages administered ranged from 600 to 1500 r, calculated as air dose at theoretical midbody line.
2. After irradiation each dog was given an intravenous infusion of 1.4 to 3.7 billion cells of his own bone marrow. This sample of autologous marrow was aspirated through a surgical window in the femur immediately prior to the animal’s irradiation and was stored in plasma and tissue culture fluid at 4 C. while awaiting use.
3. All dogs survived the acute radiation injury. There were two late deaths, one from intercurrent infection and one from small bowel obstruction.
4. The six surviving dogs are in apparent good health 5 months to 10 months after irradiation. Control dogs in this laboratory have a 100 per cent 15 day mortality after air dose of 600 r total-body irradiation.
5. A comparison with a previous series of dogs grafted with homologous smarrow shows that autologous marrow induces a recovery after lethal irradiation that is superior to the recovery induced by homologous marrow.
6. The superior results observed after autologous marrow appear attributable to a rapid postirradiation recovery of lymphoid tissue as well as bone marrow. Circulating lymphocytes reappear, lymph nodes regain normal histologic appearance, and the serum gamma globulin pattern returns to normal. These latter events do not occur promptly after infusions of homologous marrow.
