Apoptosis and its regulating mechanisms are crucial physiological events for the maintenance of the placental homostasis; and disequilibrium of these processes may compromise placental function and the success of the pregnancy. In this study, apoptosis was investigated by histomorphometry using slides stained with HE and TUNEL reaction. Besides that, Bcl-2 and caspases 8 and 3 expression were evaluated by real time polymerase chain reaction in healthy placentas under different gestacional ages. Samples of placentones of cows at 4th, 6th, and 9th months of gestation were harvested and processed. The apoptotic index gradually increased with the advance of the gestation. Bcl-2 and caspases 3 and 8 were expressed in all the studied periods, being the expression of Bcl-2 lower than that of caspase 8, which was lower than caspase 3. These results indicate that these molecules are involved in the activated apoptotic way in the placental maturation, showing a standard expression throughout the gestation and contributing for the physiological balance of the cellularity and cellular turn over in bovine placenta.
cattle; apoptosis; placenta; caspases; Bcl-2
