Toxicity Of AlCl₃on Osteoblast Of Rats Cultured In Vitro

Osteoblasts （OB） isolated from neonatal SD rats were cultured in vitro to investigate thetoxicity of AlCl₃. The OB were exposed to AlCl₃in final concentration of0.063（low-dose group,GL）,0.126（middle-dose group, GM）,0.252（high-dose group, GH） and0（control-group, GC）mg·mL-1, respectively. After24h, proliferation rates were detected by CCK-8assay. The ALPactivity and BGP content in cell culture medium were detected by colorimetric method and radioimmunoassay, respectively. Intracellular [Ca²⁺]i were detected by Fura-2/AM fluorescence.Ca²⁺-ATPase activity were measured by detecting inorganic phosphorus ion. CoL â…  and BGPmRNA expression were detected by semi-quantitative RT-PCR. CaM mRNA expression weredetected by real-time fluorescence quantification.CaM protein expression were detected byWestern blot. The study was aimed to research the toxicity of AlCl₃on OB of rats. The resultsshowed as follows：1. The half maximal inhibitory concentration （IC50） of AlCl₃was1.26±0.02mg/mL.2. The proliferation rates of OB in Al-treated groups decreased, and were significantly lowerthan that in GC. There were dose-effect relationships. It indicated AlCl₃could restrain the activityof OB.3. The CoL â… and BGP mRNA expressions were significantly lower in GL （p＜0.05） GM andGH （p＜0.01） than those in GC, ALP activity and BGP content of medium in Al-treated groupswere significantly lower than those in GC（p＜0.05ï¼›p＜0.01）. There were dose-effect relationship.It indicated AlCl₃in GM、GH can restrain the proliferation, differentiation and mineralization ofOB.4. The intracellular [Ca²⁺]i was significantly higher in GM and GH than those in GC （p＜0.01）. CaM mRNA and protein expression were significantly lower than those in GC （p＜0.01）Ca²⁺-ATPase activity was lower in GC, GM （p>0.05） and GH （p＜0.01） than that in GC. It showedAlCl₃in GM could disorder the calcium homeostasis of OB.