Histomorphometrical and proliferative aspects of placenta and uterus of the collared peccary (Tayassu tajacu)
Tatiana C. Santos1, Cristiane Tonarelli2, Fábio A. Teixeira2, Moacir F. Oliveira3, Durvanei Maria4, Patrícia Reginato4, Jose R. Kfoury Jr.2, Carlos A.L. Oliveira1, Daniela A.L. Lourenço1 and Maria A. Miglino2
1Department of Animal Science, State University of Maringá, Maringá, Paraná, Brazil, 2Department of Surgery, School of Veterinary Medicine, University of São Paulo, São Paulo, Brazil, 3Department of Animal Science, Federal Rural University of the Semi-Arid. Mossoró, Rio Grande do Norte, Brazil and 4Butantan Institute, São Paulo SP, Brazil.
Offprint requests to: Dra. Tatiana C. Santos, Department of Animal Science, State University of Maringá Av. Colombo 5790, Maringá, PR 87020-900, Paraná, Brazil. e-mail: tcsantos@uem.br
Summary. The histomorphometric and proliferative characteristics of the collared peccary (Tayassu tajacu) placenta and uterus were analyzed. The material was examined by standard histological techniques and histochemistry (PAS, Perls and Alcian Blue pH 0.5 and 2.5%) and the cellular proliferation by AgNORs and flow cytometry. All the analyzed morphometric variables differed between pregnant and non-pregnant uteri in the luteal phase using the Dunnet test. Height and gland diameter of uterine glands increased linearly during pregnancy, with an intense positive PAS and Perls reaction in all stages. The cells with more than seven AgNORs per nuclei and the cells in the G2M cell cycle phase in the maternal tissue also increased after 70 days of pregnancy. The uteroplacental ridges had a linear increase in size with two distinct areas, base and top, with uterine epithelium and trophoblastic cells changing their morphology following the placental ridge development. Flow cytometry analysis showed the percentage of cells in each cell cycle phase with a quadratic behavior for stages G2/M in the maternal tissue, suggesting an increase in proliferative capacity of maternal tissue after 65 days of pregnancy. The same quadratic effect was observed in the G0/G1 phase in both maternal and fetal tissues. Cells in apoptosis showed cubic behavior in both tissues. The morphometric and cellular dynamic aspects observed in this study have not been previously described and they extend our knowledge of functions relating to maternal-fetal dynamics in this species. Histol Histopathol 27, 793-806 (2012)
Key words: Tayassu, Epitheliochorial, Trophoblast, Flow cytometry, AgNOR
DOI: 10.14670/HH-27.793