Treatment of osteoporosis with TheraCyte-encapsulated parathyroid cells: a study in a rat model.
BACKGROUND
The purpose of this study was to evaluate parathyroid function at monthly intervals following the implantation of TheraCyte-encapsulated live human parathyroid cells into ovariectomized rats and to determine the effect on bone mineral density (BMD) 4 months after ovariectomy ( 3 months after implantation).


METHODS
Parathyroid tissues were obtained from patients undergoing surgery for secondary hyperparathyroidism. In total, 21 Sprague-Dawley rats divided randomly into three groups were subjected to one of three treatments: (1) implanted with TheraCyte A-encapsulated 4x10(6) live parathyroid cells; (2) implanted with TheraCyte B-encapsulated 4x10(5) live parathyroid cells; (3) a sham operation; the control group. Rats were ovariectomized 1 month prior to the implantation of the TheraCyte. Blood was drawn at the time of implantation and at monthly intervals thereafter for 3 months to check the levels of calcium, phosphorus and intact parathyroid hormone (iPTH). The BMD of the lumbar spine (L1-L5) and of the left femoral bone was measured with dual-energy-X-ray absorptiometry (DEXA) 1 month after ovariectomy and 3 months after implantation of the TheraCyte (4 months after ovariectomy).


RESULTS
We found that the viability ratio of cryopreserved tissues was between 55 and 79% after thawing. In the control group, the BMD of the lumbar spine (L1-L5) had not decreased significantly (p=0.237) nor had the BMD of the left femoral bone increased significantly (p=0.063) 3 months after implantation. In the TheraCyte A group, the BMD of both the lumbar spine (p=0.018) and left femoral bone (p=0.018) had increased significantly 3 months after implantation. In the TheraCyte B group, the BMD of both the lumbar spine (p=0.017) and the left femoral bone (p=0.025) had also increased significantly 3 months after implantation. Serum iPTH levels were higher in the TheraCyte A group than in the TheraCyte B group (p=0.006), and higher in the TheraCyte B group than in the control group (p=0.040). Serum calcium levels were not significantly higher in the TheraCyte group A than in the TheraCyte B group or in the control group. Serum phosphorus levels were not significantly different between the TheraCyte A and TheraCyte B groups.


CONCLUSIONS
Implantation of TheraCyte A-encapsulated 4x10(5) live parathyroid cells and TheraCyte B-encapsulated 4x10(6) cells can increase the BMD of ovariectomized rats within 3 months of implantation. Neither cause high serum calcium and low phosphorus concentrations.
Chou
F-F
FF
Department of General Surgery, Chang Gung Memorial Hospital at Kaohsiung, Chang Gung University 123, Ta-Pei Road, Niao-Sung Hsiang, Kaohsiung Hsien, Taiwan, Republic of China. choulu@ms4.hinet.net
Huang
S-C
SC
Chen
S-S
SS
Wang
P-W
PW
Huang
P-H
PH
Lu
K-Y
KY
D015502:Absorptiometry, Photon; D000818:Animals; D015519:Bone Density / Q000187:drug effects* / Q000502:physiology; D002118:Calcium / Q000097:blood; D017690:Cell Transplantation / Q000379:methods; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging; D010024:Osteoporosis / Q000628:therapy*; D010052:Ovariectomy; D010280:Parathyroid Glands / Q000166:cytology / Q000637:transplantation*; D010281:Parathyroid Hormone / Q000378:metabolism / Q000627:therapeutic use*; D010758:Phosphorus / Q000097:blood; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D014184:Transplantation, Homologous
D010281:Parathyroid Hormone; D010758:Phosphorus; D002118:Calcium