IBYME   02675
INSTITUTO DE BIOLOGIA Y MEDICINA EXPERIMENTAL
Unidad Ejecutora - UE
artículos
Título:
Expression of caspase-2, -3, -8 and -9 proteins and enzyme activity in the corpus luteum of the rat at different stages during the natural estrous cycle
Autor/es:
PELUFFO MC; BUSSMANN L; STOUFFER RL; TESONE M
Revista:
REPRODUCTION
Referencias:
Año: 2006 vol. 132 p. 465 - 475
ISSN:
1470-1626
Resumen:
Apoptosis is associated with the regression of the corpus luteum (CL)
in many species. Since caspases play a central role in apoptosis, we
studied several initiators (-2, -8, and -9) and the main effector (-3)
caspase in the CL during the estrous cycle of the rat. Two different
populations of CL (old and new) were identified on ovaries at estrus
and diestrus II (DII). Diminished (P < 0.05) luteal progesterone
content and P450scc levels suggested that functional luteolysis
occurred between the new CL at DII and old CL at estrus, whereas the
decline (P < 0.05) in luteal weight indicated that structural
regression was occurring between old CL at estrus to DII.
Immunostaining for caspase-2 in luteal and endothelial cells appeared
to increase as the luteal phase progressed, peaking at DII in the old
CL. However, caspase-8 and -9 immunostaining showed little change with
a slight increase at estrus in the old population. Notably, caspase-3
staining appeared to peak at DII in the new CL. Enzyme activity of
caspase-9 increased (P < 0.05) in the new CL at DII, followed by
that of caspase-2 and -3 in old CL at estrus. Caspase-8 activity did
not change at any stage. The number of apoptotic cells increased at DII
in the old CL. These results suggest an important role for this
protease family during early events of luteolysis in the rat estrous
cycle.