Cardiomyocyte Regeneration in the mdx @entity19 Model of XXXX .

@entity1 @entity1603 @entity296 @entity712 @entity63 @entity19 @entity299
UNASSIGNED: Endogenous regeneration has been demonstrated in the @entity1 heart after @entity63 . However, approximately one-third of cases of @entity712 are secondary to nonischemic @entity299 and cardiac regeneration in these cases remains relatively unexplored. We, therefore, aimed at quantifying the rate of new cardiomyocyte formation at different stages of nonischemic @entity296 . Six-, 12-, 29-, and 44-week-old mdx @entity19 received a 7 day pulse of @entity1603 . Quantification of isolated cardiomyocyte nuclei was undertaken using cytometric analysis to exclude nondiploid nuclei. Between 6-7 and 12-13 weeks, there was a statistically significant increase in the number of @entity1603 -labeled nuclei in the mdx hearts compared with wild-type controls. This difference was lost by the 29-30 week time point, and a significant decrease in cardiomyocyte generation was observed in both the control and mdx hearts by 44-45 weeks. Immunohistochemical analysis demonstrated @entity1603 -labeled nuclei exclusively in mononucleated cardiomyocytes. This study demonstrates cardiomyocyte regeneration in a nonischemic model of @entity1 @entity296 , controlling for changes in nuclear ploidy, which is lost with age, and confirms a decrease in baseline rates of cardiomyocyte regeneration with aging. While not attempting to address the cellular source of regeneration, it confirms the potential utility of innate regeneration as a therapeutic target.
