摘要
目的 探讨早期糖尿病肾病(DN)系膜细胞(GMC)收缩功能的变化及其与肾小球高滤过的关系。方法 Wistar大鼠正常组和糖尿病(DM)2周组,采用STZ诱导DM模型,进行成模后GMC培养,与体外高糖刺激系膜细胞对照,用Fluo-3荧光标记GMC,共聚焦显微镜测定GMC胞浆内基础Ca^(2+)水平,动态观察血管紧张素Ⅱ(Ang Ⅱ)刺激Ca^(2+)水平的变化,以及抑制蛋白激酶C(PKC)对Ca^(2+)水平的影响。结果 DM鼠的肌酐清除率(Ccr)在2周时明显升高。DM2周组GMC内基础Ca^(2+)水平低于正常,高糖组Ca^(2+)水平无明显下降,但各组对AngⅡ刺激反应均较正常有不同程度降低,以2周组最为显著。佛波酯作用24h能恢复2周组基础Ca^(2+)水平,部分恢复各组AngⅡ刺激引起的GMC内Ca^(2+)水平上升反应。结论 细胞内钙紊乱是GMC收缩失调的主要机制之一;PKC活化参与了GMC的收缩过程。GMC的收缩功能变化在DN早期肾小球高滤过的发生中起重要作用。
Objective To elucidate functional alterations of glomerular mesangial cell (GMC) contraction and its relationship with diabetic glomerular hyperfiltration. Methods Male Wistar rats were divided into groups of normal control and 2 weeks diabetes induced by STZ. GMC were cultured in the presence of normal glucose (5mM). Meanwhile in comparison GMC obstained from normal rats were cultured in the presence of 30 mM glucose for 48 h in vitro. By using laser scanning confocal microscopy (LSCM) , we measured basal calcium concentration, the changes of calcium level in response to vasoconstrictor agonist angiotensin H (Ang I ),and the effect of protein kinase C (PKC) inhibitor PMAC10 M,24 h)on cytosol calcium of GMCs. Results The creatinine clearance rate (Ccr) was increased with age in diabetic rats, reaching a peak at 2 weeks (P<0. 01), but still higher than normal control (F<0. 05). Basal calcium level of GMCs from 2-week diabetes was lower than normal, and had no significant difference in high-glucose groups compared with control. Moreover , high-glucose cultured GMCs of diabetic rat showed a lower functional capacity of elevating cytosol calcium in response to Ang I , especially in 2-week group. Inhibition of PKC completely reversed the basal calcium level of 2-week group, and partially reversed the response to Ang I of diabetic and high-glucose cultured GMC. Conclusion The disturbance of cytosol calcium might contribute to diabetic mesangial cell dysfunction. The dysfunction may play an important role in the development of early diabetic nephropathic hyperfiltration. Activation of PKC seems to involve in GMC contraction.
出处
《中国糖尿病杂志》
CAS
CSCD
2003年第2期114-117,共4页
Chinese Journal of Diabetes
基金
国家自然科学基金(39870297)
