IHEM   20887
INSTITUTO DE HISTOLOGIA Y EMBRIOLOGIA DE MENDOZA DR. MARIO H. BURGOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Peritubular Myoid Cells Contract in Both the Parallel and Transverse Axes.
Autor/es:
LOPEZ, L; LOSSINO, A.; MORALES, A.; CAVICCHIA, JC
Lugar:
San Diego, CA. USA
Reunión:
Congreso; 49th Annual Meeting of The American Society For Cell Biology; 2009
Institución organizadora:
The American Society for Cell Biology
Resumen:
Peritubular myoid cells contract in both the parallel and transverse axes.     Lopez, L.A. Losinno A.  IHEM. Mendoza.Argentina.   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.  PMCs from isolated ST segments VII-VIII of rat testis, either relaxed (control ST) or contracted with endothelin-1 (E-1 ST) were analyzed by confocal and electron microscopy to visualize the actin filament cytoskeleton (AF). PMC areas from control and E-1 ST were 938 ± 64  and 760 ± 81 (µm2 ± SEM) respectively and  x, y diameters from control and E-1 ST were x: 36 ± 1; 30 ± 2 and y: 30 ± 2;  23 ± 3 (µm ± SEM) respectively.  PMCs from 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 the ST axis. Contraction reduced the area of the PMCs, and the x and y axes and also shortered both the parallel and transverse layer of AF. 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.