Chronic anaemia causes degenerative changes in trophoblast cells of the rat placenta

Abstract

Objectives: Iron deficiency anaemia causes adverse pregnancy outcome. There are few studies on effects of anaemia on the structure of trophoblastic cells which are important in placental function. These data are important for understanding the function and disorders of the placenta. The aim of this study was to investigate the ultrastructural cellular changes associated with iron deficiency anaemia in rat placenta.

Methods: Forty-nine female Sprague-Dawley rats were randomly separated into experimental and control groups. The experimental group was rendered anaemic by removing 1.5 ml of blood per bleed on five alternate days, and the placentas were collected on gestational days 17, 19 and 21. For light microscopy, five cubic millimeter segments were fixed in 10% buffered formaldehyde solution; dehydrated in ethanol and embedded in paraffin wax. Five micron thick sections were cut, deparaffinized and stained with Hematoxylin and Eosin. For transmission electron microscopy, 1 mm3 sections were fixed in 2.5% phosphate buffered glutaraldehyde, post fixed in 2% osmium tetroxide, dehydrated in ethanol, cleared in propylene and embedded in epon resin. Ultrathin sections stained with uranyl acetate and lead citrate were examined with JEOL electron microscope.

Results: Cytotrophoblast, syncytiotrophoblast and giant trophoblastic cells of placentas of anaemic rats showed cytoplasmic and nuclear vacuolation with loss of cell margins. In addition, there was atrophy of microvilli on the cell surface, as well nuclear chromatolysis, nucleolar degeneration and appearance of dark bodies.

Conclusion: Chronic anaemia causes trophoblastic cell degeneration. This may undermine the functional integrity of the cells and constitute part of the mechanism for poor fetal outcome.

Keywords

• anaemia
• cytotrophoblast
• degeneration
• giant cells
• placenta
• syncytiotrophoblast

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