Morphological Alterations in Mouse Placenta Induced by Diazepam

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María Cristina Márquez-Orozco; María Verónica Gasca-Ramírez; Graciela de la Fuente-Juárez & Amalia Márquez-Orozco


Diazepam (DZ) is a benzodiazepine that belongs to the group of minor tranquilizers with myo-relaxing and anticonvulsant properties. DZ and its metabolites cross the placental barrier in human, monkey, hamster, and mouse, and accumulate in the placenta. Our aim was to investigate, through histological techniques, and semifine sections if DZ induces morphological changes in the placenta. Twenty female mice of the ICR strain were distributed randomly in two groups. One group (DZ) was treated from days 6 to 17 of gestation with a single daily subcutaneous (sc) dose of DZ of 2.7 mg/kg/ (bw); the second, control group (C) was treated with saline solution. All females (10 DZ and 10 C) were killed by decapitation. Placentas were extracted and fixed in phosphates-buffered 10% formaldehyde, pH 7.3, dehydrated, and embedded in paraffin to obtain 3 µm thick sections or fixed in 2.5% glutaraldehyde, post-fixed in 1% OsO4, embedded in epoxy resin. Histological sections were stained with hematoxylin-eosin or Weigert´s iron hematoxylin. Semifine sections were stained with toluidine blue. All sections were observed under comparative light microscopy. The DZ-group showed thinned placental barrier with multiple vacuoles. Nuclei of trophoblast cells (TCs) and trophoblast giant cells (TGCs) presented heterochromatin in coarse granules, atypically distributed in the karyolymph and conspicuous nucleoli. The cytoplasm of the TGCs was vacuolated and chromatin had a similar appearance to that observed in TCs. The total area of the placental barrier was measured in µm2/µm2; the area in the DZ group was reduced as compared with the C group (P<0.001). Alterations of TGCs could be due to an interaction of DZ with peripheral type benzodiazepine receptors involved in progesterone biosynthesis. Administration of DZ in mice alters the placental barrier and TGCs which could affect their physiology and causes teratogenic effects on the ovary and testis involved in steroid hormones biosynthesis.

KEY WORDS: Benzodiazepine; Diazepam; Mouse; Placenta; Histology.

How to cite this article

MÁRQUEZ-OROZCO, M. C.; GASCA-RAMÍREZ, M. V.; DE LA FUENTE-JUÁREZ, G. & MÁRQUEZ-OROZCO, A. Morphological alterations in mouse placenta induced by diazepam. Int. J. Morphol., 32(2):426-431, 2014.