Figure 1).

Initial characterization of TO-2 hamsters. a Survival rate. The 50% life expectancies for the golden (n=50), BIO14.6 (n=50) and TO-2 (n=46) hamsters were 114 weeks, 55 weeks and 38 weeks, respectively. b Semiquantitative reverse transcriptase polymerase chain reaction shows the relative expression levels of the genes involved in cardiac hypertrophy. The fewer the number of cycles needed for amplification, the more target complementary DNA (cDNA) was considered to be present. For example, 35 cycles were necessary for the detection of preproendothelin-1 (ppET-1) in golden hamsters (G), whereas 30 cycles and 25 cycles were enough in BIO14.6 (B) and TO-2 (T) hamsters, respectively. Thus, the relative expression level of ppET-1 was ordered from TO-2 to BIO14.6 to golden hamsters. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) was used as an internal standard for each template cDNA. α-sk Alpha-skeletal muscle actin; β-MHC Beta-myosin heavy chain; BNP Brain natriuretic peptide