自发性糖尿病大鼠肾脏微血管密度的实验研究

Experimental study of renal microvascular density in GK rats

关键词:  糖尿病  肾  GK  微血管密度

Key words:  diabetes  kidney  GK rats  microvascular density

摘要:

目的 观察自发性糖尿病大鼠(Goto-Kakisaki Rats, GK)肾脏微血管在糖尿病的不同发展时期的变化规律,为糖尿病肾病的血流灌注研究提供实验基础。方法 选取雄性GK大鼠和Wistar大鼠各30只,每种按周龄分组(4、12、20周各10只)。肾脏标本常规石蜡包埋切片后,用免疫组化法染色。每只肾脏标本取切片5张,每张切片皮质区、髓质区各随机观察18个视野。采用图像分析系统定量分析微血管密度。每张切片随机选取5个肾小球,采用不规则方式分割,分析其周长、面积、毛细血管密度。结果(1) GK各周龄组髓质微血管密度均小于对照组(P<0.05～P<0.01),GK组间有差异(P<0.01)。(2) GK 20周龄组肾小球微血管密度明显小于同周龄Wistar组(P<0.01)。GK组间、对照组间均存在差异(P<0.01～P<0.05)。(3) GK4周龄组肾小球平均周长明显大于同周龄Wistar(P=0.01)。不同周龄Wistar组间亦有差异(P<0.01～P<0.05)。结论 GK大鼠存在肾微血管稀少的现象,有可能是糖尿病的继发性改变之一；低周龄GK大鼠肾髓质微血管稀少可能与遗传有关。

Abstract:

Objective To investigate the variation of renal microvascular density in spontaneous diabetic Goto-Kakisaki(GK) rats and its association with the development and progression of type 2 diabetes mellitus. Methods Thirty male GK rats aged 4, 12 and 20 weeks(n=10 in each age group) were used in the study; and 30 Wistar rats of same ages(n=10 in each group) served as control group. The kidney specimens were stained by immunohistochemical method after embedded sections of paraffin. A minimum of 18 fields per slide and 5 slides per group were randomly taken, quantitative analysis of microvessel density in cortex and medulla of kidney specimens were performed by image analysis system. Five glomeruli were randomly selected in each slide and the circumference, area and capillary density of glomeruli were measured. ResultsThe microvessel density of the medulla in all age groups of GK rats was lower than that in control group(P<0.05), and there was a significant difference among different age groups of GK rats(P<0.01). The glomerular microvessel density in GK rats at age of 20 weeks was significantly lower than that of the same age group of Wistar rats(P<0.01). The average circumference of glomeruli in DK rats at age of 20 weeks was significantly larger than that of the same age Wistar control rats(P=0.01). There were also differences among different age groups of Wistar rats. ConclusionsThe reduced renal microvascular density in GK rats might be secondary diabetes mellitus, however, the reduced renal medulla microvascular density in young age GK rats may be of genetic feature.