The rodent endometrium undergoes remarkable modifications during pregnancy, resulting from a redifferentiation of its fibroblasts. During this modification (decidualization), the fibroblasts transform into large, polyhedral cells that establish intercellular junctions. Decidualization proceeds from the subepithelial stroma towards the deep stroma situated next to the myometrium and creates regions composed of cells in different stages of differentiation. We studied by autoradiography whether cells of these different regions have different levels of macromolecular synthesis. Radioactive @entity1522 or radioactive @entity597 were administered to @entity19 during estrus or on different days of pregnancy. The animals were killed 30 min after injection of the precursors and the uteri were processed for light microscope autoradiography. Silver grains were counted over cells of different regions of the endometrium and are reported as the number of @entity575 grains per area. Higher levels of incorporation of @entity1522 were found in pregnant animals as compared to animals in estrus. In pregnant animals, the region of decidual cells or the region of fibroblasts transforming into decidual cells showed the highest levels of synthesis. Radioactive @entity597 incorporation, on the other hand, was generally higher in nonpregnant animals. Animals without decidual cell transformation (nonpregnant and 4th day of pregnancy) showed a differential incorporation by subepithelial and deep stroma fibroblasts. This study shows that regional differences in synthetic activity exist in cells that are in different stages of transformation into decidual cells as well as in different regions of the endometrium of nonpregnant @entity19 .

Autoradiography reveals regional metabolic differences in the endometrium of pregnant and nonpregnant XXXX .

@entity19 :: ('10090', 'Species') :: ['mice'] @entity1522 :: ('CHEBI:33709', 'Chemical') :: ['amino acids'] @entity575 :: ('MESH:D012834', 'Chemical') :: ['silver'] @entity597 :: ('CHEBI:16189', 'Chemical') :: ['sulfate']
@entity19 :: (10090,Species) :: ['mice']
