THE SYNCYTIAL TISSUE TRIAD - A MODEL FOR UNDERSTANDING HOW GAP-JUNCTIONS PARTICIPATE IN THE LOCAL-CONTROL OF PENILE ERECTION

Recent findings from both clinical and experimental studies document t he importance of syncytial relaxation and contraction of corporal smoo th muscle to penile erection and detumescence, respectively. However, the mechanism(s) permitting coordinated response generation among the vast array of largely inexcitable corporal smooth muscle cells is uncl ear. In this report the compelling evidence for a major role of interc ellular communication through gap junctions to erectile function is re viewed. Moreover, a novel concept is advanced to explain more fully th e putative mechanistic basis for integrative erectile tissue biology. Specifically, the presence of gap junctions, in concert with the auton omic nervous system and myogenic intracellular signal transduction mec hanisms, is postulated to form a ''syncytial tissue triad'' that is la rgely responsible for the local modulation of corporal smooth muscle t one. It is reasonable to assume that the existence of this ''syncytial tissue triad'' confers a plasticity adaptability, and flexibility to erectile function that may well account for the observed diversity of mechanisms known to regulate penile erection as well as the multifacet ed etiology of erectile dysfunction.