ERYTHROPHAGOCYTOSIS IN THE CAPRINE TROPHOBLAST

The mechanism of iron transfer by extravasation of maternal blood in t he maternal-fetal interface and the subsequent phagocytosis of the ery throcytes by the trophoblast cells was described in ovine, bovine and other species. This research was performed due to the absence of studi es on this process in the goat. Fragments of placentomes were obtained from 9 adult goats of an unspecified breed and were separated into Gr oups A, B and C, based on 90, 120 and 150 d of gestation, respectively . Fragments of 3 placentomes were obtained from each animal of all gro ups. The first of them was removed from the base, the second from the middle part and the third from the end of the gestational uterine horn . The fragments were fixed in Bouin solution and histologically proces sed according to the usual paraffin inclusion techniques. The slides w ere stained by hematoxilin-eosin and potassium ferrocyanide and examin ed under light microscopy. The erythrophagocytosis (EP) process of the trophoblast was identified in all the examined histological sections, throughout the gestation and for each placentome. An accumulation of spots of blood was observed only in the maternal-fetal interface locat ed in the arcade zone of the placentome. The main cells of the trophob last of these areas presented an intense phagocytic activity and the o bservation of erythrocytes with hemossiderin pigments in their citopla sm was possible. The trophoblast epithelium of these areas was thicker and with a columnar aspect than the cubic aspect observed in other ar eas. The trophoblast binucleate cells do not seem to participate in EP . Our findings indicate that the phagocitosis process of the maternal erythrocites by the trophoblast also occurs in caprine species, indica ting that this could be a mechanism of transplacentary transfer of iro n in this species.