Connexin45 is the first connexin to be expressed in the central conduction system of the mouse heart.

摘要: Gap junctions are clusters of transmembrane channels that link the cytoplasmic compartments neighbouring cells to form sieve-like conduits for direct cell transfer small signalling molecules and ions, a function necessary tissue homeostasis, development differentiation (1–3). In cardiac muscle, key gap is electrical coupling individual myocytes mediate orderly spread action potentials throughout heart (4). junction comprise pairs connexons (hemichannels), one contributed by each apposed cells. Each connexon comprises hexamer six proteins. These constituent proteins, termed connexins, multi-gene family conserved To date, 16 different genes have been identified in mammalian (5). Most tissues, including heart, express multiple connexins (6). vitro experiments shown composed properties unitary conductance, voltage sensitivity molecular permeability (7). Hence, variations pattern expression 43, 40 45, hypothesized be determinants electrophysiological specialization regions heart. We others tissues impulse generation conduction system do indeed particular patterns connexin (8–12). Connexin45 present all parts adult rodent whereas connexin40 not quite as extensive, being confined central core within connexin45-expressing tissues. Connexin43, most abundant working myocardium barely detectable (atrioventricular [AV] node, His bundle branches). Expression connexin43 both regulated at mRNA level during (13). Connexin40 widely expressed embryonic day (E) 11 ventricles atria, but from E14 becomes preferentially concentrated ventricular system, although remains high atria (14,15). A downregulation connexin45 gene products has occur mouse (16), little information available on sites this connexin. The aim study was determine spatial developing heart.