肝素对大鼠下切牙釉原蛋白水平及细胞凋亡的影响

目的建立肝素诱导骨质疏松大鼠模型,观察肝素的应用对大鼠下切牙釉原蛋白水平及其细胞凋亡的影响。方法取24只4周龄清洁级Sprague-Dawley(SD)大鼠随机分为两组,实验组每日于腹部皮下注射肝素1U/g,对照组于相同部位注射等体积0.9%氯化钠溶液。4周后取大鼠右侧股骨测骨密度值。同时取下颌骨,沿正中联合分为两份,一侧颌骨及下切牙脱钙后制作石蜡切片,行釉原蛋白免疫荧光染色;另一侧脱钙后制作石蜡切片,行原位末端标记(TUNEL)染色,观察下切牙细胞的凋亡情况。实验数据采用SPSS17.0统计软件包进行统计学分析。结果实验组大鼠股骨的骨密度值为(0.185±0.006)g/cm2,低于对照组的(0.196±0.011)g/cm2;实验组下切牙釉原蛋白免疫荧光染色强度为(0.0432±0.0043),低于对照组的(0.0570±0.0096);两组骨密度及荧光强度差异均具有统计学意义(P<0.05)。实验组未见细胞凋亡发生,对照组可见个别成牙本质细胞及中间层细胞凋亡阳性着色。结论肝素可诱导大鼠骨质疏松,降低下切牙釉原蛋白表达及抑制细胞凋亡的发生。

The effect of heparin on amelogenin content and apoptosis of odontogenic cells in rat lower incisor

Objective To establish heparin-induced osteoporosis model in rat and investigate the amelogenin content and the apoptosis of odontogenic cells in rat lower incisors.Methods Twenty-four Sprague-Dawley(SD) rats were divided into 2 groups randomly.The experimental group was injected with heparin at the abdomen subcutaneous with 1 U/g each day,and the control group was injected same volume of normal sodium(NS) at the same site.All rats were sacrificed and their right femurs were obtained to measure the bone mineral density (BMD) 4 weeks later,the mandibles were harvested and divided into two parts along the centric junction.Immunofluorescence and TUNEL stain were performed.The data were statisticaly analyzed by SPSS 17.0 software.Results The right femur BMD was (0.185 ± 0.006) g/cm2 in the experimental group while it’s (0.196 ± 0.011) g/cm2 in the control group.The fluorescence intensity of amelogenin of lower incisors immunofluorescence stain is (0.0432 ± 0.0043) in the experimental group albeit it is (0.0570 ± 0.0096) in the control group.The difference between these groups was statistically significance (P < 0.05).A few odontoblasts and stratum intermedium cells in control group were apoptosis positive by TUNEL stain.In contrast,there was no apoptosis cell in the heparin group.Conclusions Heparin could lead to osteoporosis and reduce the content of amelogenin,as well as inhibit apoptosis odontogenic cells in rat lower incisor.