外源性干细胞因子对糖尿病胃轻瘫大鼠胃动力的影响

目的 探讨外源性干细胞子(Stem cell factor,SCF)对糖尿病胃轻瘫大鼠(diabetic gastroparesis,DGP)胃电及胃阻抗的影响.方法 30只SD雄性大鼠随机分为实验组和对照组,实验组采用一次性腹腔注射链脲佐菌素(streptozotocin,STZ) 50 mg/kg并高糖高脂饲料喂食建立DGP模型；成模后随机分为糖尿病组(DM组,n=8)、糖尿病+外源性干细胞因子治疗组(DM+ SCF组,n=8)；DM+ SCF组腹腔注射SCF 0.4 ug/(kg·d),共15天,对照组和DM组每天腹腔注射等量的磷酸盐缓冲液(pH=7.4).阻抗式胃动力系统检测大鼠胃动力和同步胃电,透射电镜观察胃窦平滑肌细胞超微结构的变化.结果 DM组大鼠胃电节律紊乱,胃电主功率百分比较对照组显著降低(P＜0.01)；DM组大鼠阻抗主功率百分比明显降低(P＜0.01),阻抗胃动过缓功率百分比明显升高(P＜0.01)；DM大鼠予SCF干预后,胃电、胃阻抗主功率百分比均有所改善(p ＜0.01；P＜0.05)；DM组大鼠胃窦平滑肌细胞胞核肿胀、肌浆网、内质网扩张,部分细胞胞质内细胞器溶解、消失；DM组大鼠予SCF干预后胃窦平滑肌细胞超微结构改善,电镜下仅见平滑肌细胞胞核轻度肿胀,密斑、密体、肌丝稍减少,余细胞器未见明显异常改变.结论 外源性SCF能显著改善DGP大鼠的胃电,并能部分改善其胃蠕动,其机制与胃窦平滑肌结构的改善有关.

Effects of Exogenous Stem Cell Factor on Gastric Motility in Diabetic Gastroparesis Rats

Objective To investigate the effects of exogenous stem cell factor （SCF） on the gastric electrical activity and gastric impedance in rats with diabetic gastreparesis. Methods 30 Male SD Rats were randomly divided into experimental group and control group. The rats in ex- perimental group were intraperitoneally injected with STZ at dosage of 50mg/kg and fed with high sugar high fat diet, while normal diet for control group. Eight weeks later, the rats in experimental group had complication of diabetic gastroparesis which were randomly divided into diabetes mellitus （DM） group （ n = 8 ） and DM ＋ SCF group （ n = 8 ）. The rats in DM ＋ SCF group were intraperitoneally injected with exoge- nous SCF 0. 4 ug/（ kg · d ）for 15 days,and the rats in control group and DM group were intraperitoneally injected with the same amount of phosphate buffer（ pH = 7.4）. gastric electrical activity and gastric impedance were detected by impedance gastric motility acquisition system, which was made by Cbongqing university of posts and Telecommunications; the ultrastructure of smooth muscle in the gastric antrum were assessed by transmission electron microscopy. Results DM group had dysrythmia, the percentage of dominate frequency of gastric electrical ac- tivity were significantly lower than that in the control group （P 〈 0. 01 ） ;DM group had disordered gastric motility, the percentage of domi- nate frequency of gastric impedance were significantly lower than that in the control group（ P 〈 0. 01 ）, the percentage of bradygastria fre- quency of gastric impedance were significantly higher than that in the contrei group （ P 〈 0. 01 ）. The percentage of dominate frequency of gastric electrical activity and gastric impedance were improved in DM ＋ SCF group （ P 〈 0. 01 ; P 〈 0. 05 ）. The cell nucleus swell, sarco- plasmic reticulum and endoplasmic reticulum expansion, part of the sarcoplasmic organelles dissolve and disappear in DM group. The cell nu- cleus have slight swelling, dense patch, dense body and myoneme only have little reduce in DM ＋ SCF group. Conclusion Gastric electrical activity were improved by exogenous SCF obviously;and the gastric peristalsis were improved by exogenous SCF partly, which may be relevant with the improvement of the ultrastructure of gastric antrum smooth muscle ceils.