Histoquímica e morfometria da placenta de ratas tratadas com dexametasona

Abstract

Pesq. Vet. Bras. 34(7):703-708, julho 2014 703 RESUMO.-A dexametasona, um glicocorticóide sintético, tem a capacidade de atravessar a placenta aumentando o nível de circulação de corticosteróides da mãe para o feto durante a prenhez. Quando administrada nas fases finais da prenhez pode produzir efeitos indesejáveis na formação da placenta e em vários órgãos da prole. Assim, o presente estudo objetivou investigar o efeito da administração da dexametasona (0,8mg/dia/animal) nos cinco primeiros dias da prenhez, sobre o desenvolvimento placentário de ratas. Utilizou-se 30 ratas albinas, divididas em dois grupos: Grupo I -ratas prenhes sem aplicação de dexametasona, sacrificadas ao 7 o e 14 o dia; Grupo II -ratas submetidas à aplicação de dexametasona nos cinco primeiros dias de prenhez, sacrificadas ao 7 o e 14 o dia. Os resultados mostraram que a dexametasona não afetou o número e a histologia dos sítios de implantação, porém, promoveu alteração no disco placentário ocasionando hipertrofia na camada de células trofoblásticas gigantes. Não foram evidenciadas alterações no teor de colágeno, porém houve interferência no metabolismo do glicogênio no espongiotrofoblasto trofospongio. Na morfometria de linhas houve diferença entre os grupos na região de labirinto e células trofoblásticas gigantes, porém a morfometria de pontos só ratificou as alterações percebidas na região do labirinto. The dexamethasone, a synthetic glucocorticoid, has the ability to cross the placenta by increasing the level of movement of corticosteroids from mother to fetus during pregnancy. When administered in the late stages of pregnancy can produce effects undesirable on placental formation. The present study aimed to investigate the effect of administration of dexamethasone (0.8mg/day/animal) in the first five days of pregnancy, on placental development in rats. We used 30 albino rats, divided into two groups: Group I -pregnant rats without the application of dexamethasone, sacrificed to the 7 th and 14 th day. Group II -rats subjected to the application of dexamethasone in the first five days of pregnancy, sacrificed to the 7 th and 14 th day. The results showed that dexamethasone did not affect the number and histology of the implantation sites, but promoted changes in the disk placental causing hypertrophy in trophoblastic giant cell layer. No changes were found in the content of collagen, but there was interference with the metabolism of glycogen in spongiotrophoblast. The morphometry of lines showed, a difference between groups in the region of labyrinth and trophoblast giant cell. However, in morphometry of points there was a difference between groups in the region of labyrinth.INDEX TERMS: Dexamethasone, placenta, histochemical morphometry, rat.

Effect of the Aqueous Extract of Chrysobalanus icaco Leaves on Maternal Reproductive Outcomes and Fetal Development in Wistar Rats

“…To quantify the constituent elements of the placental disc layers, a 110-point graticule was used to identify the structures and cells, which were classified as (1) maternal vascularization; (2) small trophoblastic cells, undifferentiated (in contact with fetal vessels); (3) intermediate cells (in contact with maternal vessels); (4) giant trophoblastic (binucleated) cells; (5) syncytial cells (near the trophoblast region); and (6) mesenchyme, in the trophospongial region. In the labyrinth region, they were classified as (1) syncytial trophoblast; (2) fetal vessel wall; (3) lumen of fetal vessels; and (4) labyrinthine vascular bed (maternal vessel), and were analyzed with the 40× objective, with 10 fields randomly chosen per slide, and with three repetitions, making a total of 1100 points [ 27 , 28 ].…”