engleski

Proliferation of decidual cells in rat embryos is greater before than after gastrulation

During pregnancy, endometrial cells undergo series of morphological and physiological alterations leading to transformation into decidual cells. This is essential for the successful implatantion and placentation of the early embryo and its proper development. As in humans, similar alterations occur in rodents ; thus, rat can be considered an appropriate experimental model to study decidual development in humans. The purpose of this study was to compare the proliferation of rat decidual cells before and after embryo gastrulation stage. Pregnant rats were euthanized on the 8th day (before gastrulation) and on the 11th day (after gastrulation) of gestation. Uteruses were isolated under binocular magnifying scope and found deciduomas fixed in 4% formaldehyde. One part was stained with H&E for histological analysis whereas the other part (from 6 randomly selected deciduomas) was used for PCNA (proliferating cell nuclear antigen ; a marker of cell proliferation) immunohistochemistry. The PCNA-positive cells were counted using stereological method for numerical density (Nv) on Weibel’s multipurpose test grids with 42 points and analyzed with Ellipse 3D program. We found that there were significantly more proliferating decidual cells before gastrulation (Nv = 39, 151 ; 8th day of gestation) than after gastrulation stage (Nv = 13, 301 ; 11th day of gestation) (p<0.01, Student's t test) In conclusion, our result shows that during gestation, decidua is characterized by cell proliferation that predominates in early pregnancy but decreases later on, after gastrulation is completed, as decidua assumes other functions of protecting the developing embryo.

decidua; trophoblast; proliferation; gastrulation; placenta

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