Abstract:

BACKGROUND: Microencapsulation has been widely used in various experimental studies. Microencapsulated parathyroid transplantation has become a hot issue, but the better transplantation site and the mechanism underlying failed transplantation are urgently to be solved.
OBJECTIVE: To investigate the therapeutic effects of xenotransplantation of microencapsulated parathyroid tissue on treatment of hypoparathyroidism in Wistar rats and to determine the optimal transplantation site and the mechanism underlying failed transplantation.
METHODS: Wistar rat models of hypoparathyroidism were developed. At 4 weeks after model establishment, rat models were randomly allocated to four groups: renal adipose capsules, chest sternocleidomastoid muscle, and empty microcapsule control groups. Microcapsuled parathyroid tissues were transplanted into renal adipose capsules and chest sternocleidomastoid muscle in renal adipose capsules group and chest sternocleidomastoid muscle group respectively. Empty microcapsules without parathyroid were transplanted into renal adipose capsules in empty microcapsule group. Total serum calcium was measured every other week. In the 16th week, transplant beds were retrieved and subjected to electron microscopic examination. 
RESULTS AND CONCLUSION: There was no significant difference in serum calcium level between renal adipose capsule group and chest sternocleidomastoid muscle group during 16 weeks (P > 0.05). The serum calcium level in the chest sternocleidomastoid muscle group decreased between 16-20 weeks. There were many fiber tissues surrounding the microencapsules in the chest sternocleidomastoid muscle group. Parathyroid tissues can be protected successfully from Aliginate-Ba capsules and then survive functionally for a long time. The renal adipose capsule is the better transplantation site than chest sternocleidomastoid muscle.