RESUMEN
OBJECTIVE: To explore the possible mechanism of Huoxue Qianyang Formula (HXQYF), a compound traditional Chinese herbal medicine, in reversing the left ventricular hypertrophy (LVH) of spontaneous hypertensive rats (SHRs) by analyzing the expressions of mRNAs and proteins of proto-oncogenes c-fos and c-myc in left ventricular muscle. METHODS: The experimental study was carried out in SHRs, the sex- and age-matched Wistar-Kyoto (WKY) rats were served as normal control (n=5, normal saline 10 ml/kg daily). Twenty-five SHRs were randomly divided into five groups: untreated group (n=5, normal saline 10 ml/kg daily), high-dose HXQYF-treated group (n=5, 0.84 g/ml HXQYF, 10 ml/kg daily), medium-dose HXQYF-treated group (n=5, 0.42 g/ml HXQYF, 10 ml/kg daily), low-dose HXQYF-treated group (n=5, 0.21 g/ml HXQYF, 10 ml/kg daily) and cilazapril-treated group (n=5, 1 mg/ml cilazapril, 10 ml/kg daily). The drugs were intragastrically administered once daily for 14 weeks. The expressions of mRNAs and proteins of proto-oncogenes c-fos and c-myc in left ventricular muscle were detected separately by in situ hybridization histochemical method and immunohistochemical method. RESULTS: Compared with the normal control group, the expressions of mRNAs and proteins of proto-oncogenes c-fos and c-myc in left ventricular muscle were significantly increased in untreated group (P<0.01). After treatment, the expressions of c-fos and c-myc mRNAs in left ventricular muscle in HXQYF-treated groups were significantly down-regulated as compared with those of the untreated group (P<0.05). The expressions of c-myc protein were also significantly decreased in high- and medium-dose HXQYF-treated groups as compared with the untreated group (P<0.05), but it had no significant effects in protein expression of c-fos in the three HXQYF-treated groups. CONCLUSION: HXQYF can inhibit the expression of c-myc in ventricular hypertrophy tissue, which may be the mechanism in treating LVH of hypertension.