[Effect of herbal cake-partitioned moxibustion on renal function and expression of renal connective tissue growth factor, integrin-linked kinase and bone morphogenetic protein-7 in chronic renal failure rabbits]

Objective: To observe the effect of herbal cake-partitioned moxibustion on renal function and expression of connective tissue growth factor (CTGF), integrin-linked kinase (ILK) and bone morphogenetic protein-7 (BMP-7) in chronic renal failure (CRF) rabbits, so as to reveal its mechanisms underlying improvement of CRF.

Methods: Twenty-four male New Zealand rabbits were randomly divided into control, model, medication and herbal cake-partitioned moxibustion (moxibustion) groups (n=6 rabbits in each group). The CRF model was established by gavage of suspension of Adenine (150 mg·kg^-1·d^-1) for 21 days. Herbal cake-partitioned moxibustion was applied to "Mingmen"(GV4) and bilateral "Shenshu"(BL23), "Pishu"(BL20) and for 5 moxa-cones every time. Rabbits of the medication group was treated by gavage of Losartan Potassium (2.33 mg·kg^-1·d^-1). All the treatments were conducted once daily,12 times a course for consecutive 3 courses with a two-day rest after each course of treatment. Serum creatinine (Scr), blood urea nitrogen (BUN) and 24 h urine protein contents were detected by using an automatic biochemical analyzer. The expression levels of CTGF, ILK and BMP-7 proteins and mRNA in the kidney tissue were determined by Western blot and quantitative real time-PCR, separately.

Results: Following modeling, Scr and BUN and 24 h urine protein contents were significantly increased in the model group in comparison with the control group (P<0.01). After the intervention, Scr and BUN contents were all significantly decreased in both the moxibustion and medication groups relevant to the model group (P<0.01), suggesting an improvement of the renal function. Compared with the control group, the expression levels of ILK and CTGF mRNAs and proteins were obviously up-regulated (P<0.01), and those of BMP-7 mRNA and protein significantly decreased in the model group (P<0.01). In comparison with the model group, the expression levels of ILK and CTGF mRNAs and proteins were significantly down-regulated in the two treatment groups (P<0.01, P<0.05), and those of BMP-7 mRNA and protein markedly increased in the two treatment groups (P<0.01). In comparison with the medication group, the expression level of ILK protein was significantly up-regulated (P<0.01) and BMP-7 protein was significantly down-regulated (P<0.01) in the moxibustion group. No significant differences were found between the medication and moxibustion groups in down-regulating the levels of Scr, BUN and 24 h urine protein and expression of ILK mRNA, CTGF mRNA and protein and BMP-7 mRNA(P>0.05).

Conclusion: Herbal cake-partitioned moxibustion can improve renal function in CRF rabbits, which may be related to its effects in suppressing the expression of ILK and CTGF, and in up-regulating the expression of BMP-7 in the kidney tissue.