The effect of cryopreservation on hormone secretion in vitro and morphology of human parathyroid tissue.

The hormone secretion from human parathyroid tissue autografted after cryopreservation can fail frequently. In this study we examined the effects of the cryopreservation procedure on parathyroid hormone secretion in vitro and the viability of parathyroid cells to identify possible reasons for graft failure. Cryopreservation did not affect quantitative parathyroid hormone release from single-cell suspensions or its calcium-and magnesium-dependent regulatory mechanisms. However, morphometric analysis of thawed 1 mm3 graft particles showed various degrees of necrosis when compared with fresh grafts. Thus partial necrosis of cryopreserved tissue appears to contribute to poor transplantation results compared with immediate replantation of fresh parathyroid tissue. This limitation can be overcome by increasing the number of frozen graft particles used for autotransplantation. The percentage of viable cells should be accounted for by morphometric analysis and this factor used when calculating the number of graft particles employed.