[Effects of zinc deficiency on bone mineralization and its mechanism in rats].
OBJECTIVE
To study the influence of zinc deficiency on bone mineralization.


METHODS
Thirty Wistar rats were randomly divided into three groups with ten in each group, i.e., zinc-deficient group (ZD), control group, and pair-fed group. Histomorphological changes of bone mineralization, bone mineral content and bone density, bone contents of zinc, calcium, phosphorus, magnesium, manganese, copper and hydroxyproline, and serum levels of parathyroid hormone, calcitonin and osteocalcin in the rats were measured.


RESULTS
The results showed that the mineral deposit rate and bone contents of zinc, phosphorus and hydroxyproline, and serum levels of calcitonin and osteocalcin lowered significantly in ZD group, as compared with those in the control and pair-fed groups, with (3.26 +/- 0.34) micro m/d, (64.54 +/- 2.34) g/kg, (54.4 +/- 9.5) mg/kg, (9.28 +/- 1.62) g/kg, (41.2 +/- 13.5) micro g/L, (82 +/- 30) micro g/L in ZD group; (5.37 +/- 0.53) micro m/d, (69.01 +/- 4.05) g/kg, (117.4 +/- 8.0) mg/kg, (11.31 +/- 1.30) g/kg, (68.3 +/- 14.4) micro g/L, (131 +/- 46) micro g/L in the control group; and (5.45 +/- 0.30) micro m/d, (67.81 +/- 3.56) g/kg, (106.7 +/- 8.4) mg/kg, (10.88 +/- 1.47) g/kg, (63.7 +/- 12.0) micro g/L, (120 +/- 52) micro g/L in the pair-fed group, respectively. While the time for mineralization lag and osteoid maturation obviously prolonged, (1.08 +/- 0.19) d and (7.12 +/- 2.30) d in ZD group, (0.39 +/- 0.06) d and (2.21 +/- 1.12) d in the control group, and (0.40 +/- 0.06) d and (2.12 +/- 0.58) d in the pair-fed group, respectively. In addition, bone mineral content and bone density and serum parathyroid hormone in ZD group decreased significantly and were lower than those in the control group, but not significantly different from those in the pair-fed group. There were no significant difference in femoral contents of calcium, magnesium, manganese and copper between the ZD group and the control and pair-fed groups.


CONCLUSIONS
Zinc deficiency could lower the contents of parathyroid hormone and calcitonin in blood circulation affecting bone mineral deposit and causing defect in bone mineralization.
Zhang
Yue-hong
YH
Institute of Health and Environmental Medicine, Tianjin 300050, China.
Cheng
Yi-yong
YY
Hong
Yan
Y
Wang
Dong-lan
DL
Li
Shu-tian
ST
D000818:Animals; D015519:Bone Density / Q000502:physiology*; D001842:Bone and Bones / Q000378:metabolism*; D002113:Calcification, Physiologic / Q000502:physiology*; D002116:Calcitonin / Q000097:blood; D005260:Female; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D015032:Zinc / Q000172:deficiency*
D010281:Parathyroid Hormone; D002116:Calcitonin; D015032:Zinc