In vivo survival of rabbit platelets by rapid freezing and thawing

Conclusions

Our studies showed that at very rapid cooling rates of more than 100° C. per second in liquid helium the platelets are damaged and after thawing do not circulate in the peripheral blood. We don't have any explanation for this. But it seems that ice crystals are not the only reason for cell damage. The experiments with different thawing rates indicate that approximately 45° C. per second is optimum. While glycerol in a concentration of 10 per cent was not suitable for preservation of rabbit platelets at the high freezing and thawing rates used, the results with DMAC were encouraging.

Toxicity of DMAC for human platelets and for animals and man should be determined. In addition, it should be clarified whether human platelets behave similarly to those of the rabbit frozen in liquid nitrogen without protective agents. If platelets could be frozen without cryophylactic additives, all questions of toxicity both to the platelets and the recipient would be eliminated.