Effects of calcitonin and parathyroid hormone on calcification of primary cultures of chicken growth plate chondrocytes
Effects of calcitonin and parathyroid hormone on calcification of primary cultures of chicken growth plate chondrocytes
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DOI：
10.1359/jbmr.1997.12.3.356
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发表时间：
1997-03-01
影响因子：
6.2
通讯作者：
Wuthier, RE
中科院分区：
文献类型：
--
作者：
Ishikawa, Y;Wu, LNY;Wuthier, RE
很少有研究致力于阐明降钙素（CT）和甲状旁腺激素（PLH）对生长板软骨细胞（直接参与纵向骨生长和临时钙化的细胞）的作用。使用在不添加β-甘油磷酸盐的情况下钙化的禽类生长板软骨细胞的原代培养物来研究合成的人CT和1 - 34牛PTH对（1）细胞分裂和生长;（2）Ca 2+和无机磷酸盐（Pi）的沉积;（3）碱性磷酸酶（AP）的活性，一种长期与矿化过程相关的酶;（4）蛋白聚糖的水平;和（5）胶原蛋白的合成，从第6天开始连续加入到汇合前培养物中，直到帽状，CT（1 - 30 nM）和PTH（0.1 - 1.0 nM）增加的矿物质沉积;在10 nM CT下，在第18 - 21天之间观察到最大增加（175 - 260%）和0.5 nM PTH（类似于170 - 280%），均p <0.001，er对细胞蛋白或AP特异性活性无显著影响，而PTH增加细胞蛋白、DNA、蛋白聚糖，AP活性与培养液中II、X型胶原和纤维连接蛋白水平呈双相反应;在第15 - 18天之间在0.5nM时观察到最大增加，更长的曝光（第21 - 27天），以较高水平（5 - 10 nM）的PTH引起AP活性显著降低，但：这些结果表明CT和PTH可以直接作用于软骨细胞以刺激矿化，但PTH特异性地刺激生长板软骨细胞的细胞分裂和细胞及细胞外蛋白的合成，讨论了这些发现对Ca~（2+）稳态和骨形成的影响。
Few studies have been directed toward elucidating the action of calcitonin (CT) and parathyroid hormone (PLH) on growth plate chondrocytes, cells directly involved in longitudinal bone growth and provisional calcification, In this study, primary cultures of avian growth plate chondrocytes that calcify without the supplement of beta-glycerophosphate were used to investigate the effects of synthetic human CT and 1-34 bovine PTH on (1) cell division and growth; (2) the deposition of Ca2+ and inorganic phosphate (Pi); (3) the activity of alkaline phosphatase (AP), an enzyme long associated with the mineralization process; (4) the levels of proteoglycans; and (5) the synthesis of collagens, Added continually to preconfluent cultures from day 6 until hat-vest, CT (1-30 nM) and PTH (0.1-1.0 nM) increased mineral deposition; the maximal increase was seen between days 18-21 at 10 nM CT (175-260%) and 0.5 nM PTH (similar to 170-280%), both p < 0.001, er had no significant effect on cellular protein, or AP-specific activity, whereas PTH increased cellular protein, DNA, proteoglycan, and collagen content of the cultures in a dosage-dependent manner, AP activity and levels of Type II and X collagens and fibronectin in the culture medium showed a biphasic response to PTH; maximal increases were seen at 0.5 nM between days 15-18, Longer exposure (days 21-27) to PTH at higher levels (5-10 nM) caused a marked decrease in AP activity but: a lesser decrease in the collagens, These results indicate that CT and PTH can act directly on chondrocytes to stimulate mineralization, but that PTH specifically stimulated cell division and synthesis of cellular and extracellular proteins by growth plate chondrocytes, The implications of these findings with regard to Ca2+ homeostasis and bone formation are discussed.