Jiedu tongluo baoshen gelation capsule for protecting the kidney of rats with diabetes mellitus and its effect on the expression of connective tissue growth mRNA

Xianjun ZHAO; Cai LI; Zheng NAN; Yue DENG

ABSTRACT

BACKGROUND:

Connective tissue growth factor (CTGF) has very strong regulative effect on the differentiation and proliferation of renal cells as well as the synthesis and degradation of extracellular matrix. Its abnormal expression plays a key role in the process of fibrous degeneration of various renal diseases including diabetic nephropathy.

OBJECTIVE:

To observe the protective effect ofjiedu tongluo baoshen gelatin capsule on renal disease in rats with diabetes mellitus and its effect on the expression of renal CTGF mRNA.

DESIGN:

A randomized controlled experiment taking animals as subjects.

SETTING:

Institute of Traditional Chinese Medicine, Changchun College of Traditional Chinese Medicine; Department of Pathology, Institute of Regenerated Medical Sciences, Jilin University MATERIALS Totally 46 Wistar rats, of clean degree, male and female in half, weighing 150 to 200 g, were used in the experiment. Jiedu tongluo baoshen gelatin capsule was provided by Preparation Room, Traditional Chinese Medicine Hospital of Jilin Province (Batch No. 2002101, composed of Renshen, Huangqi, Shengdi, Gouqizi, Zhimuv Digupiv Huanglian,Zhenhua, Jinyinhua, Dahuang, Danshen, Yimucao and so on, 0.25 g/pill)and benazepril (Provided by Beijing Nuohua Pharmaceutical Company,Batch No. 01046) were used in the experiment.

METHODS:

This experiment was carried out in the Department of Pathology, Institute of Regenerated Medical Sciences, Jilin University from May 2002 to January 2003. ① Totally 46 Wistar rats used in the experiment were randomly divided into 4 groups normal control group (n=10), model group (n=12), benazepril-treated group (n=12) and traditional Chinese medicine-treated group (n=12).Rats of normal control group were intraperitoneally injected of natrium citricum buffer solution of same volume; Rats of other groups were intraperitoneally injected of 50 mg/kg streptozotocin which was dissolved by 0.1 mol/L citric acid buffer solution before use(pH 4.2). Seventy-two hours after modeling, venous blood was collected from the tails to measure the levels of fasting blood glucose and urine glucose.Blood glucose ≥ 16.7 mmol/L and urine glucose over 卅 suggested diabetic models were successful. Rats of benazepril-treated group were performed intragastric administration of benazepril suspension of 15 mg/(kg·d);Rats of traditional Chinese medicine-treated grou p were performed intragastric administration ofjiedu tongluo baoshen gelatin capsule suspension of 5 g/(kg ·d); Rats of normal control group and model group were performed intragastric administration of the same volume of running water on each morning, once a day, 12 weeks in total. ② Levels of blood glucose,urea nitrogen, serum creatinine and urinary albumin excretion rate were measured 12 weeks after administration; Level of angiotensin Ⅱ of renal tissue was measured with radioimmunoassay; Levels of renal fibronectin and type Ⅳ collagen protein expression were measured with immunohistochemical method; Connective tissue growth factor gene expression of renal cortex was measured with reverse transcription-polymerase chain reaction and renal histological observation was also performed. ③ Analysis of variance was used in the intergroup comparison.MAIN OUTCOME

MEASURES:

Biochemical index of blood and urine,level of angiotensin Ⅱ of renal tissue, pathological morphology, expression of fibronectin and type Ⅳ rabbit anti-rat collagen protein and expression of connective tissue growth factor mRNA

RESULTS:

Five, four and three rats died in the process of experiment respectively in model group, benazepril-treated group and traditional Chinese medicine-treated group, finally, 10,7,8 and 9 rats entered the stage of result analysis respectively in normal control group, model group, benazepril-treated group and traditional Chinese medicine-treated group. ① The ratio between body mass and renal mass was significantly higher in the model group than in the normal control group (P ＜ 0.05),but was significantly lower in the benazepril-treated group and traditional Chinese medicine-treated group than in the model group (P ＜ 0.01). ② Fasting blood glucose was significantly higher in the model group than in the normal control group (P ＜ 0.01),but was significantly lower in the traditional Chinese medicine-treated group than in the model group and benazepril-treated group (P ＜ 0.01). ③ Levels of urea nitrogen, serum creatinine, creatinine clearance, urinary albumin excretion rate and angiotensin Ⅱ of renal tissue were significantly higher in the model group than in the normal control group (P ＜ 0.01), but significantly lower in the benazepril-treated group and traditional Chinese medicine-treated group than in the model group (P ＜ 0.05-0.01 ). ④Pathomorphological change of renal tissue was very severe in the model group,but very mild in the benazepril-treated group and traditional Chinese medicine-treated group. ⑤Fibronectin and type Ⅳ rabbit anti-rat collagen protein expression were significantly higher in the model group than in the normal control group (P ＜ 0.01), those were significantly lower in the benazepril-treated group and traditional Chinese medicine-treated group than in the model group, but higher than normal control group (P ＜ 0.01). ⑥Expression of CTGF mRNA of renal cortex of model group was 2.65 times that of normal control group. Expression of CTGF mRNA of benazepriltreated group and traditional Chinese ine-treated group was decreased by 23.68% and 26.32%, respectively (P ＜ 0.05 or 0.01).

CONCLUSION:

Jiedu tongluo baoshen gelatin capsule has protective effect on diabetic nephropathy, which might be implemented by reducing the level of angiotensin Ⅱ of renal tissue and down-regulating the expression of CTGF mRNA of renal cortex of rats with diabetes mellitus, so as to reduce the deposition of extracellular matrix.