Cardiovascular gap junctions: functional diversity, complementation and specialization of connexins

This chapter reviews recent results related to the characterization of cardiovascular vascular gap junctions. The functions of connexin40, -43 and -45 have been studied using targeted mouse mutants of these genes. The following results are discussed: impaired myocardial conduction and vasodilatation along arterioles of connexin40 deficient mice; additive effects of connexin40 and -43 on ventricular conduction and cardiac morphogenesis; vascular maturation depending on connexin45 during embryonic development; and functional replacement of connexin43 by connexin32 or -40 and endothelium-speciric ablation of connexin43 in transgenic mice.