In Vitro and in Vivo Assessment of the Viability of Dog Marrow after Storage

Assessment has been made of the ability of dog marrow cells to survive storage at 4 C. and at -79 C. Survival has been assessed in vitro by measurements of rates of DNA synthesis and in vivo by ability to restore marrow functions in lethally irradiated recipients.

Dog bone marrow cells synthesize DNA in vitro at values 30 to 80 per cent of normal after storage for 24 hours at 4 C. DNA synthesis is reduced to very low levels by storage for 96 hours at 4 C. Eight lethally irradiated beagle dogs (600 to 1500 r) survived acute irradiation effects and returned to normal health after receiving intravenous infusions of autologous bone marrow that had been stored at 4 C. for 24 hours or less. One dog, similarly irradiated, failed to survive when given marrow stored for 96 hours at 4 C. A tenth dog did survive when given an exceptionally large quantity of marrow stored for 96 hours at 4 C.

Dog marrow cells synthesize DNA in vitro at values 40 to 50 per cent of normal in samples stored at -79 C. in 15 per cent glycerol for periods up to 17 days. Five lethally irradiated beagle dogs (1000 to 1500 r) survived acute irradiation effects and returned to normal health after receiving intravenous infusions of autologous marrow that had been stored at -79 C. in 15 per cent glycerol. One other dog, similarly irradiated and treated, regained marrow function but died of hepatitis. Two other irradiated dogs similarly treated did not regain marrow function and died. These two had received exceptionally small infusions of marrow cells.

The observations demonstrate that dog marrow can be preserved satisfactorily at 4 C. for 24 hours and in glycerol at -79 C. for longer periods. The capacity of the stored marrow to synthesize DNA in vitro has correlated well with its ability to induce recovery in lethally irradiated autologous recipients. DNA synthesis in vitro appears to be a useful index of the ability of marrow cells to proliferate in vivo.