Electrotonic loading of anisotropic cardiac monolayers by unexcitable cells depends on connexin type and expression level.

ABSTRACT: Understanding how electrotonic loading of cardiomyocytes by unexcitable cells alters cardiac impulse conduction may be highly relevant to fibrotic heart disease. In this study, we optically mapped electrical propagation in confluent, aligned neonatal rat cardiac monolayers electrotonically loaded with cardiac fibroblasts, control human embryonic kidney (HEK-293) cells, or HEK-293 cells genetically engineered to overexpress the gap junction proteins connexin-43 or connexin-45. Gap junction expression and function were assessed by immunostaining, immunoblotting, and fluorescence recovery after photobleaching and were correlated with the optically mapped propagation of action potentials. We found that neonatal rat ventricular fibroblasts negative for the myofibroblast marker smooth muscle alp

SUBMITTER: McSpadden LC 

PROVIDER: S-EPMC2724091 | biostudies-literature | 2009 Aug

REPOSITORIES: biostudies-literature