To investigate effects of recombinant human brain natriuretic peptide on cardiac function and sodium current in rats with chronic heart failure.

  METHODS  The rat model with heart failure was constructed by transverse aortic constriction (TAC).Sixty male Sprague-Dawley rats aged (6-8) weeks were randomly divided into four groups: sham operation group (sham group), model group, rhBNP group, captopril (CAP)group; Rats in rhBNP group and CAP group were given rhBNP (25 μg/kg)/time, CAP (2 mg/kg)/time, once daily, and intragastric administration once every 4th week after modeling operation. After 4 weeks of administration, HE staining were used to observe the heart tissue lesions in rats.Whole-cell patch-clamp technique for detect the sodium ion current in rat myocardial cells. Western blot was used to detect the expression of Nav1.5 protein.

  RESULTS  Compared with the sham group, CHF pathological symptoms were obvious in the model group, sodium current was significantly decreased, and the expression of Nav1.5 protein was significantly decreased. the difference was statistically significant (P<0.05); Compared with model group, CHF pathological symptoms were significantly relieved in the rhBNP group, CAP group, sodium current was significantly increased, and the expression of Nav1.5 protein was significantly increased, the difference was statistically significant (P<0.05).

  CONCLUSION  rhBNP can improve cardiac function, inhibit ventricular remodeling in CHF rats, and prevent the decrease of sodium current in CHF rat myocardial cells, and increase the expression of Nav1.5 protein.