The effects of prolactin (LTH) on calcium metabolism of bone. -Formation of osteoclast-like multinucleated cells in culturs of calvaria and bone marrow cells-

催乳素(LTH)影响脊椎动物的钙调节。提示LTH可能在骨钙代谢中发挥作用。我之前曾报道过LTH能增强体外培养的大鼠颅骨细胞的钙摄取。影响骨钙代谢的PTH和1，25-(OH)_2D_3可引起骨髓细胞中破骨细胞样多核细胞(OMN细胞)数量的增加。研究表明，LTH直接影响大鼠颅骨和骨髓来源的培养细胞中OMN细胞的形成。时程研究表明，在加入LTH后的6小时内，这种显著增加。在所有的研究中，在培养的各个时期添加LTH的效果没有差别。增加的OMN细胞表现出典型的破骨细胞的形态特征，包括破骨细胞的标志酶TRACP。结果表明，LTH可诱导破骨细胞形成类似于PTH和1，25(OH)_2D_3的破骨细胞，提示LTH可能在骨钙代谢中起重要作用。

Prolactin (LTH) influences calcium regulation in verteblate. It is possible that LTH has a role in calcium metabolism of bone. I have previously reported that LTH enhances calcium uptake in rat calvarial cells in vitro. PTH and 1,25-(OH)_2D_3 affecting calcium metabolism of bone cause an increase in the number of osteoclast-like multinucleated cell (OMN cell) in bone marrow cultures.Present study examined that LTH affects directly on OMN cell formation in cultured cells derived from calvaria and bone marrows of rat and mouse.LTH (200 g/ml) caused an increase in the number of OMN cells (200-900% over control values). Time course studies showed that this increase was significantly observed within 6 hours after the addition of LTH. The effect was not different among the all studies with LTH addition at any period in cultures. Increased OMN cells exhibited typical morphological features of osteoclasts in cluding TRACP, a marker enzyme for osteoclasts. When the OMN cells were cultured on sperm whale dentine in the presence of LTH, numerous resorption lacunae were formed.These results indicated that LTH induces the formation of osteoclasts similar to those of PTH and 1,25 (OH)_2D_3.The evidence from this study suggest that LTH may play a significant role in calcium metabolism of bone.