IHEM   20887
INSTITUTO DE HISTOLOGIA Y EMBRIOLOGIA DE MENDOZA DR. MARIO H. BURGOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Contractile apparatus of seminiferous tubule myoid cells
Autor/es:
LOSINNO AD; MORALES A; BERTOLDI MV; AMAYA MC; COSTANTINO VV; LOPEZ LA
Lugar:
Puerto Madryn, Cubut
Reunión:
Congreso; XLVI. Reunion Anual SAIB; 2010
Institución organizadora:
Sociedad Argentina de Investigacion Bioquimica
Resumen:
CB-C04
CONTRACTILE APPARATUS OF SEMINIFEROUS
TUBULE MYOID CELLS
Losinno AD, Morales A, Bertoldi MV, Amaya MC, Costantino VV,
L¨®pez LA
IHEM-CONICET. Facultad de Ciencias. M¨¦dicas. UNCuyo.
Mendoza. Argentina. E-mail: alosinno@fcm.uncu.edu.ar
Myoid cells (MC) surround the seminiferous tubules (ST) and
express contractile proteins of muscle cells like ¨¢-actin and myosin.
Previous works postulated an orthogonal display of actin filaments
(AF) forming a net.
In this study we analyzed the distribution of AF and myosin II
filaments (MF) of MC by confocal microscopy and TEM. Adult rat
ST segments were isolated and maintained in control conditions or
contracted with 50 nM ET-1. The segments were hatched with anti
¨¢-actin-FITC or anti SMMII-IgG-Cy3 antibodies. Other segments
were processed by conventional technique for TEM study.
Confocal microscopy images of ST segments showed that MC
contain both AF and MF distributed in two independent layers
instead of a net: the inner layer with filaments perpendicular to the
tubular axis and the external layer with filaments parallel. We
confirmed this observation by TEM. In ST segments treated with
ET-1, MC have smaller cellular area (1127¡À77,9 ¦Ìm ¡À SEM) and
bigger high (4,7¡À0,4 ¦Ìm ¡À SEM) than controls (1823¡À68,8 ¦Ìm and
3,3¡À0,2 ¦Ìm respectively). TEM showed that MC of contracted
segments have folded both nuclei and basement membranes,
intertwined AF and MF, and a major anchorage of filaments to the
plasma membrane.
The knowledge of the participation of AF and MF in MC
contraction is very important to understand the role that MC carry
out in the transport of sperm cells in the ST.