Natural embryonic death in the plain viscacha lagostomus maximus: are there previous anatomo-histological variations that would intervene in the differential survival of the implantations?

F; CG BARBEITO; G RANEA; EL PORTIANSKY; MA MIGLINO&FLAMINI M.A

Simposio; International Federation of Placenta Associations 2019 (IFPA2019) and 8th Latin American Symposium on Maternal-Fetal Interaction and Placenta (VIII SLIMP); 2019

In the rodent, Lagostomus maximus, there is physiological embryonic death. The cranial and middle implantations of the uterine horns (UH) are reabsorbed while the caudal continue with their development. The causes are still unknown. Our objective was to study non pregnancy UH by morphometry and ultrasonography to determine if possible anatomo-histological variations could be involucrated. Three females were anesthetized and placed in dorsal decubitus to observe and measure both UH by ultrasonography with the Mindray Z5 device. After sacrifice, the UH were sectioned in 7 sectors following its cranial-caudal axis. Samples were processed for inclusion in paraffin, cut at 3μm and stained with Gomori´s trichrome. From each section 2 zones were observed and photographed (vertex and center). Using ImageJ software, thicknesses were measured in: uterine wall (EW), endometrium (E), myometrium (M), internal muscle layer (iM), outer muscular layer (oM) and vascular layer (V). Ultrasonography showed that UH are tubular and swell in the cranio-caudal direction. An echogenic uterine wall and a light with normal content were evidenced. In longitudinal section, it was observed that the diameter of both horns increased in the craniocaudal direction due to the increase in the thickness of the uterine wall. The vertex and center means showed significant differences for EW, E, M, iM, oM and V (p≤0,05) in each sector, so the organ presented an oval contour (thin vertices and central region). wide). Significant differences were detected among the 7 sectors for the same measures; the organ presents an increase in its wall, due to a greater thickness of all the tunics and layers studied, in the cranial-caudal direction. The greater thickness of endometrium and myometrium in the caudal sectors could the complete development of the conceptus, while the specific increase in the value of the V would suggest a greater vascular supply.