The relationship between the proliferation of parathyroid cell in rabbit with primary hyperparathyroidism and the bone mineral density

Abstract

Objective To evaluate the relationship between the proliferation of parathyroid cell in rabbit with primary hyperparathyroidism (PHPT) and the bone mineral density (BMD). Methods Eighty adult Chinese rabbits were randomly and equally divided into two groups. The contrast group was fed with normal diet ( Ca ∶ P, 1.0 ∶ 0. 7 ) and the experimental group was fed with high phosphate diet ( Ca ∶ P,1.0∶7.0) to establish the animal model of PHPT. At 3, 4, 5, and 6 months after the diet, bone mineral density of the rabbits was measured by the quantity CT (QCT). Then, the parathyroid and bone of the rabbits were removed for pathological examination. The number of parathyroid cell in PHPT was calculated.Proliferation was determined by immunohistochemistry of proliferation cell nuclear antigen ( PCNA ) and Bcl-2. The t test and Logistic regression was used to analyze the difference of data of two groups. Result The number of parathyroid cell in PHPT group was 1.61 times than that in the contrast group[ (673 ± 151 ) HP,(418 ± 25 ) HP,P ＜0. 01]. The rate of PCNA positive-cell was significantly increased in PHPT group than that in contrast group [(50.52 ± 11.62)％o, (26.70 ± 2. 78 )％, P ＜ 0.01], and so was Bcl-2[ (460. 37 ± 190. 05 )‰, (67. 02 ±:4. 38 )％‰,P ＜0. 05]. The value of BMD was significantly decreased in PHPT group than that in contrast group [ ( 152. 5 ± 34. 3 ), ( 188.6 ± 12. 2 ) g/cm3, P ＜ 0. 05]. There was a negative correlation between BMD and PCNA (r ＝ -0. 749, P ＜ 0. 05 ) and between BMD and Bcl-2 (r ＝-0.800, P ＜ 0. 05 ) in PHPT group. Conclusion The BMD of PHPT is related to the parathyroid cells proliferation which provide a reliable method for early diagnosis of PHPT. Key words: Hyperparathyroidism, primary; Bone density; Proliferating cell nuclear antigen; Animal experimentation