Saitta J C, Lipkin E W, Howard G A
Department of Medicine, University of Washington, Seattle 98195.
J Bone Miner Res. 1989 Jun;4(3):379-86. doi: 10.1002/jbmr.5650040312.
A hypothesis has been advanced that parenteral solutions as commonly formulated for use in clinical practice have a toxic effect on cell metabolism. A specific component of these solutions, sodium acetate, has been suggested to disrupt normal bone turnover and therefore to contribute to the osteopenia observed in patients receiving hemodialysis and parenteral nutrition (PN). We developed an in vitro model to test the hypothesis that sodium acetate at concentrations that are infused in PN solutions has a deleterious effect on bone metabolism. Osteoblasts and preosteoblasts from 16- to 17-day-old embryonic chick calvaria, and tibiae and femora from 10-day-old embryonic chicks were grown in BGJb medium (control) or in BGJb medium plus sodium acetate (5, 10, or 20 mM). Calvarial cell proliferation was quantified by direct cell counts as well as by incorporation of [3H]TdR into DNA as an index of cell proliferation. Calvarial cell alkaline phosphatase activity was quantified by the ability of extracts of the cultured cells to hydrolyze p-nitrophenyl phosphate to p-nitrophenol, and bone growth was determined by measuring final dry weight. Calvarial cell counts as well as DNA synthesis showed a dose-dependent decrease in the presence of sodium acetate (5-20 mM) compared with controls. [3H]TdR incorporation was decreased a mean 19% with 5 mM, 38% with 10 mM, and 63% with 20 mM acetate. Alkaline phosphatase activity per cell increased 48% with 5 mM, 140% with 10 mM, and 355% with 20 mM acetate. Cell viability as assessed by trypan blue exclusion was identical for test and control media (greater than 95%).(ABSTRACT TRUNCATED AT 250 WORDS)
一种假说认为，临床实践中常用的胃肠外营养液对细胞代谢具有毒性作用。这些溶液的一种特定成分——醋酸钠，被认为会扰乱正常的骨转换，从而导致接受血液透析和胃肠外营养（PN）的患者出现骨质减少。我们建立了一个体外模型，以检验以下假说：PN溶液中输注浓度的醋酸钠对骨代谢具有有害影响。将16至17日龄胚胎鸡颅骨的成骨细胞和前成骨细胞，以及10日龄胚胎鸡的胫骨和股骨，培养于BGJb培养基（对照）或添加醋酸钠（5、10或20 mM）的BGJb培养基中。通过直接细胞计数以及将[3H]TdR掺入DNA来量化颅骨细胞增殖，以此作为细胞增殖的指标。通过培养细胞提取物将对硝基苯磷酸水解为对硝基苯酚的能力来量化颅骨细胞碱性磷酸酶活性，并通过测量最终干重确定骨生长情况。与对照组相比，在醋酸钠（5 - 20 mM）存在的情况下，颅骨细胞计数以及DNA合成均呈剂量依赖性下降。5 mM醋酸钠使[3H]TdR掺入量平均降低19%，10 mM降低38%，20 mM降低63%。每细胞的碱性磷酸酶活性在5 mM醋酸钠时增加48%，10 mM时增加140%，20 mM时增加355%。通过台盼蓝排斥法评估的细胞活力在试验组和对照组培养基中相同（大于95%）。（摘要截取自250字）
