| 摘 要： | AIM:To investigate mediating and reguatory effects of osteoblastic gap junctional interecllular communication(GJIC)on low-dose parathyroid hor-mones(PTH)-stimulated bone formation activties in vitro.METHODS:Rat calvarial osteoblasts(ROBs) in cultures wer divided into three groups ac-cording to the different mode of exposure.Group A:vehicle (sodium acetate,SA)-treated group;GroupB:1&;#215;10^-8mol/L hPTH(1-34)intermittent exposure group;GroupC:1&;#215;10^-8mol/LhPTH(1-34)+1&;#215;10^-7mol/L TPA exposure group.48h incubation cycles in three groups were repeated for eight times.GJIC and mineralized bone nodules formation in three groups were detected using Lucifer Yellow(LY) scrape loading dye transfer(SLDT) and mineralized nodule staining together with nodule index,respectively.RESULTS:At various measuring time points of SA&;#215;6h+TPA&;#215;1h in group C,LY(+) cell numbers were 6.8&;#177;2.5,19.5&;#177;6.5,14.0&;#177;3.6 and 5.7&;#177;2.4,respectively.Diffusion and transfer of LY fluorescent probe was much more noticeably discerned in group B than in group A and C(P&;lt;0.01).Mineralized bone nodule indices were 45.2&;#177;12.5,88.0&;#177;15.3and 38.5&;#177;17.9 in group A,B and C respectively.Bone formation activity was much better revealed in group B than in group A and C(P&;lt;0.01）,whereas no statistically significant difference of bone formation activities were found in group A compared with group C(P=0.465).CONCLUSION:Mediations and regulations of the coordinating signals in osteoblastic network via GJIC essentially contribute to PTH-stimulated bone anabolism.However,disruption of GJIC not only hinders osteoblastic intercellular coordination but also frustrated PTH-induced bone formation activities in vitro.Therefor,GJIC may evidently play imprtant roles in regulations on low-dose PTH-induced bone formation.
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