HISTO-MORPHOLOGY OF THE PLACENTA OF LAGOSTOMUS MAXIMUS

FRAUNHOFFER NICOLAS.; STELLA INES; JENSEN FEDERICO; LEOPARDO NOELIA.; INSERRA PABLO.; VITULLO ALFREDO.

Ciudad autonoma de Buenos Aires

Jornada; XI Jornadas anuales de la Sociedad Argentina de Biología; 2009

Sociedad Argentina de Biología

Six to 10 embryos are implanted in L. maximus but only one or two are gestated to term (those nearest to the cervix). This selective embryo resorption could relate to a functional placenta deficiency, sustained through the prevalence of a massive abundance of secondary corpora lutea throughout gestation. The aim was to characterize the histo-morphology of the placenta of L. maximus throughout gestation. Five placenta belonging to early- (n=2), mid- (n=2) and late- (n=2) developing L.maximus embryos. Placenta were perfused and fixed with 4% paraformaldehide. Sagital sections were stained with haematoxylin and eosin, Masson´s trichrome and PAS. L. maximus showed a labyrinth placenta divided into lobes separated by interlobular trophoblast. In the lobes the maternal blood formed spaces surrounded by syncytial trophoblast. In interlobular regions, the vascular maternal channels converge into bigger channels these receiving blood from two or more adjacent lobes. The subplacenta is organized as lamellae of cytotrophoblast over a layer of mesenchymal tissue. In conclusion, the L. maximus´ placenta is a lobulated one, with maternal-fetal exchange occuring in the labyrinths. It also shows a typical histricognatha subplacenta.