Fig. 7.

Comparison of cellular to intact heart properties in binary versus CSQ hearts. Cardiac myocyte contractile function and cell length, measured in vitro (left column), were compared with FS and LVEDD measured in vivo (right column) at the indicated ages for binary and CSQ animals. A: SS (32 myocytes from 17 mice) and FS in 12W binary hearts (n = 26) were both larger than the SS (27 myocytes from 15 mice) and the FS in CSQ (n = 29) hearts at 12W. When the binary animals advanced to 16W, there was a significant decrease in FS compared with that in 12W binary animals (P < 0.05, 1-way ANOVA followed by posttest comparison). B: resting cell length of 12W binary cardiac myocytes (86 myocytes from 47 binary mice) and LVEDD in 12W binary hearts (n = 26) was both less than the corresponding cell length (87 myocytes from 48 mice) and LVEDD (n = 29) of 12W CSQ animals. At 16W, the cell length of binary myocytes (12 myocytes from 8 mice) became longer than that of the 12W binary myocytes (P < 0.05) and was similar to that of the 12W CSQ myocytes (P > 0.1, 1-way ANOVA followed by posttest comparison). Similarly, the LVEDD of 16W binary mice (n = 12) also increased compared with that of 12W binary hearts (n = 26; P < 0.05) and became similar to the LVEDD of the 12W CSQ hearts (P > 0.1, 1-way ANOVA followed by posttest comparison).