NPPB and left ventricular hypertrophy: Interestingly, a recent study showed that while the levels of Ac-H3K9 on ANP, BNP, and β-MHC promoters are significantly increased during left ventricular hypertrophy stage in Dahl salt-sensitive rats after 6 weeks salt exposure, the levels of Ac-H3K122 on ANP, BNP and β-MHC promoters are elevated at heart failure stage after 15 weeks salt exposure compared to age matched salt-resistant rats [45].