[pCKM-mPTH recombinant plasmid therapy for hypoparathyroidism: an in vivo experimental research with rats]

To investigate the effect of gene therapy with pCKM-mPTH recombinant plasmid on hypoparathyroidism.

Thirty male Sprague Dawley rats were randomly divided into three groups: group A, undergoing fake operation and then injection of normal saline into the quadriceps muscle of the left leg; group B, undergoing parathyroidectomy and injection of blank pcDNA3.1(+) plasmid into the quadriceps muscle of the left leg; and group C, undergoing parathyroidectomy injection of pCKM-mPTH plasmid containing gene of mutated proparat-hormone into the quadriceps muscle of the left leg. Peripheral blood was collected from each rat before operation and 3, 5, 6, 7, 9, 12, 15, 20 and 30 days after operation. Radioimmunoassay was used to detect the level of parathyroid hormone.

The level of paratheproid hormone (PTH) of the group B was 10.61 ng/dl +/- 0.86 ng/dl before injection of blank plasmid and gradually decreased after the injection, for example, 10.39 ng/dl +/- 0.36 ng/dl 1 day after the injection and 9.45 ng/dl +/- 2.64 ng/dl 60 days after the injection. The level of PTH of the group C was 10.75 ng/dl +/- 0.45 ng/dl before the injection of pCKM-mPTH plasmid and gradually increased after the injection, for example, 28.39 +/- 0.22 ng/dL 1 day after the injection, significantly higher than that before the injection, peaked on the 6th day (43.28 ng/dl +/- 2.45 ng/dl), then gradually decreased, and reached 15.32 ng/dl +/- 0.26 ng/dl on the 60th day. However, the levels of PTH in the group C at any time-point were all significantly higher than those of the group B (all P < 0.01). Symptoms of hypoparathyroidism were not observed in the rats of the group C.

pCKM-mPTH recombinant plasmid therapy is effective in treatment of hypoparathyroidism.