SUCCESSFUL ALLOTRANSPLANTATION OF MICROENCAPSULATED PARATHYROIDS IN RATS

Allotransplantation of parathyroid tissue in humans is desirable for t reating long-term hypoparathyroidism (e;g., after inadvertent removal of parathyroid glands during thyroid surgery). Until now, parathyroid allotransplantation was not used clinically because its advantages wer e outweighted by the need of immunosuppression. To overcome the immuno genicity of the tissue to be transplanted, we employed the method of m icroencapsulation; first tried in islet cell transplantation for exper imental allotransplantation of parathyroid tissue. We have been able t o achieve long-term success in a rat model. After isolation and tissue culture, tissue pieces from parathyroid glands of 280 Lewis rats were encapsulated in barium alginate and grafted into hypocalcemic DA rats . From the 7th to the 90th day after transplantation the recipient rat s (DA rats) showed a normal serum calcium concentration. This is the f irst report of successful long-term survival and function of microenca psulated allotransplanted parathyroid tissue.