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

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 amino acids or radioactive sulfate were administered to mice 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 silver grains per area. Higher levels of incorporation of amino acids 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 of synthesis. Radioactive sulfate 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 mice.

Ultra-estrutura do epitélio sulcular na gengiva humana clinicamente normal e na doença periodontal / Junctional epithelium ultrastructure in clinically normal human gingiva and in periodontal disease

O objetivo desta pesquisa é estudar, no mesmo paciente, a ultra-estrutura do epitélio sulcular tanto na normalidade clínica quanto frente à doença periodontal. Cinco pacientes que apresentavam áreas de normalidade clínica e de doença periodontal foram estudados. Três biópsias gengivais de cada área foram obtidas, utilizando-se a incisão de bisel invertido. Os tecidos assim obtidos foram submetidos ao processamento histológico para microscopia óptica e eletrônica. Os resultados observados foram os seguintes, para as amostras representativas de doença periodontal: 1) As cisternas perinucleares apresentaram-se ocasionalmente alargadas. 2) O espaço intercelular estava aumentado e freqüentemente preenchido por um material granular eletrondenso. 3) Desmossomas típicos, embora em menor quantidade, foram observados. 4) A lâmina basal freqüentemente apresentava-se interrompida no epitélio sulcular severamente alterado pela doença periodontal

Contact between trophoblast and antimesometrial decidual cells in the mouse

La interfase entre las células gigantes del trofoblasto y las células deciduales antimesometriales fueron analizadas entre los días 7 y 11 de preñez en el ratón con microscopía. Estrecha aposición de las membranas celulares y áreas especializadas de la membrana celular similares a las uniones intercelulares del tipo adherens fueron encontradas entre las células trofoblásticas y deciduales