NPPB and cardiac hypertrophy: Data obtained demonstrate that following 2 weeks of TAC the BL/6N substrain aged 10 or 12 weeks manifested cardiac dysfunction, whilst most mice aged 8 weeks had cardiac hypertrophy with preserved cardiac function concomitant with abundant fibrosis and increased gene expression of brain natriuretic peptide (BNP), collagen gene 1α1 (Col1α1) and collagen gene 3α1(Col3α1).