通络明目膏对糖尿病大鼠视网膜血管内皮生长因子表达的影响

Effects of Tongluo Mingmu Ointment on the expression of retinal VEGF in diabetic rats

目的探究通络明目膏对糖尿病大鼠视网膜血管内皮生长因子(VEGF)表达的影响。方法选择60只实验大鼠,应用随机数表法将其分为空白组(n=10)、阳性对照组(n=10)、模型组(n=10)以及通络明目膏低剂量组(n=10)、通络明目膏中剂量组(n=10)、通络明目膏高剂量组(n=10)。除空白组外,其余5组大鼠通过高脂高糖饮食+2%链脲佐菌素注入建立糖尿病视网膜病变模型,同时通络明目膏低剂量组、通络明目膏中剂量组、通络明目膏高剂量组分别灌胃10、40、60 mg/(kg·d)通络明目膏,阳性对照组灌胃等效剂量100 mg/(kg·d)的羟苯磺酸钙胶囊,模型组、空白组灌胃等量蒸馏水,干预12周。比较各组大鼠外周血血清胰岛素样生长因子1(IGF-1)、血管内皮素(ET-1)、VEGF表达量以及大鼠视网膜组织中血管内皮生长因子受体2(VEGFR-2)、VEGF表达量的差异。结果干预12周后,模型组大鼠视网膜组织VEGFR-2、VEGF阳性表达以及血清IGF-1、ET-1、VEGF表达量显著高于其他5组(P<0.05)。通络明目膏低剂量组的血清IGF-1、ET-1、VEGF表达量及视网膜组织VEGFR-2、VEGF阳性表达明显高于阳性对照组(P<0.05);通络明目膏中剂量组的血清IGF-1、ET-1、VEGF表达量及视网膜组织VEGFR-2、VEGF阳性表达与阳性对照组比较,差异无统计学意义(P>0.05);通络明目膏高剂量组的血清IGF-1、ET-1、VEGF表达量及视网膜组织VEGFR-2、VEGF阳性表达均显著低于阳性对照组(P<0.05)。镜检下见,与模型组大鼠比较,阳性对照组、通络明目膏低剂量组、通络明目膏中剂量组、通络明目膏高剂量组大鼠视网膜各层次排列更整齐,组织水肿及毛细血管扩张显著减轻,且随着通络明目膏使用剂量增加,视网膜毛细血管减轻程度升高。结论糖尿病大鼠的外周血和视网膜组织内存在VEGF过量表达,而经高剂量通络明目膏干预后能够显著改善视网膜微血管变化,发挥视网膜保护作用。

Objective To explore the effects of Tongluo Mingmu Ointment on the retinal vascular endothelial growth factor(VEGF)in diabetic rats.Methods A total of 60 experimental rats were selected and divided into the blank group(n=10),positive control group(n=10),model group(n=10),low-dose Tongluo Mingmu Ointment group(n=10),medium-dose Tongluo Mingmu Ointment group(n=10)and high-dose Tongluo Mingmu Ointment group(n=10)according to the random number table method.The rats in the positive control group,the model group,low-dose Tongluo Mingmu Ointment group,medium-dose Tongluo Mingmu Ointment group and highdose Tongluo Mingmu Ointment group were induced with a high-fat and high-sugar diet combined with 2%streptozotocin(STZ)solution to establish models of rats with diabetic retinopathy.Meanwhile,the low-dose CMM group,medium-dose Tongluo Mingmu Ointment group and high-dose Tongluo Mingmu Ointment group were gavaged with 10,40 and 60 mg/(kg·d)of Tongluo Mingmu Ointment respectively,and the positive control group was gavaged with 100 mg/(kg·d)of calcium dobesilate capsules of the equivalent dose.The model group and the blank group were gavaged with distilled water of the same amount.All groups were intervened for 12 weeks.All groups were compared for the differences in the expression of insulin-like growth factor-1(IGF-1),endothelin-1(ET-1)and VEGF in the peripheral blood and the expression of vascular endothelial growth factor receptor 2(VEGFR-2)and VEGF in the retinal tissues of rates.Results After 12 weeks of intervention,the positive rates of VEGFR-2 and VEGF in the retinal tissues of rats,as well as the expression of serum IGF-1,ET-1 and VEGF model group were significantly higher than other 5 groups(P<0.05).The expression of serum IGF-1,ET-1 and VEGF and the positive rates of VEGFR-2 and VEGF in the retinal tissues in the low-dose Tongluo Mingmu Ointment group were significantly higher than those in the positive control group(P<0.05).There were no statistically significant differences between the medium-dose Tongluo Mingmu Ointment group and the positive control group in the expression of serum IGF-1,ET-1 and VEGF and the positive rates of VEGFR-2 and VEGF in the retinal tissues(P>0.05).However,the expression of serum IGF-1,ET-1 and VEGF and the positive rates of VEGFR-2 and VEGF in the retinal tissues in the high-dose Tongluo Mingmu Ointment group were significantly lower than those in the positive control group(P<0.05).In addition,compared with the model group,more neatly arranged retinas and significantly alleviated tissue edema and capillary dilation were observed in the positive control group,low-dose Tongluo Mingmu Ointment group,medium-dose Tongluo Mingmu Ointment group and high-dose Tongluo Mingmu Ointment group by microscopic examination,and the alleviation degree of retinal capillary dilation was higher with the increase of Tongluo Mingmu Ointment dose.Conclusion VEGF is overexpressed in the peripheral blood and retinal tissues of diabetic rats,and high-dose Tongluo Mingmu Ointment can significantly improve the retinal m icrovascular changes and protect retinas.