Organization of actin filament network in peritubular myoide cells of rat testis

LOPEZ LA

Huerta Grande, Cordoba

Conferencia; . XVII Jornadas Científicas de la Sociedad de Biología de Córdoba.; 2009

Sociedad de Biología de Córdoba

Organization of actin filanent network in peritubular myoide cells of rat testis. Lopez, L.A. IHEM. Mendoza. Testicular peritubular myoid cells (PMCs), the main cellular component of the seminiferous tubule (ST) wall, are contractile cells that express cytoskeletal markers of true smooth muscle, such as alpha-isoactin, F-actin, and myosin. The contractile activity of PMCs is responsible for the contraction of STs underlying the transport of spermatozoa and testicular fluid and, at least in part, for sperm release during spermiation.  The actin cytoskeleton of PMCs from isolated segments VII-VIII of rat testis ST were analyzed by confocal and electron microscopy. PMCs of these segments contain two layers of actin filaments. One layer is localized underneath the nucleus and close to the basal membrane of the seminiferous epithelium and is oriented transversally to the major ST axis.  The other layer is localized above the nucleus and oriented parallel to ST axis. The contraction induced by endothelin-1 reduced the area of PMCs and reoriented the parallel layer of actin filaments without changing the organization of the transverse layer. As result of the contraction, the parallel layer of actin filaments redistributed to the periphery of the cell.   These results lead us to conclude that the particular organization of actin filaments in PMCs allow them to contract the cell in both parallel and transverse axes.