Early and natural embryonic death in Lagostomus maximus: association with uterine glands, vasculature and musculature

ACUÑA F; BARBEITO CG; PORTIANSKY EL; RANEA G; NISHIDA F; MIGLINO MA; FLAMINI MA

JOURNAL OF MORPHOLOGY

WILEY-LISS, DIV JOHN WILEY & SONS INC

Lugar: New York; Año: 2020

0362-2525

The uterus is an organ with great plasticity due to the morphophysiological changes it experiences during the estrous cycle and pregnancy. In mammals, pregnancy requires diverse molecules (sex hormones, growth factors and cytokines, among others) for promoting uterine remodeling to favor implantation, placentation, and embryo/fetus survival and growth. The hystricognathi rodent Lagostomus maximus (plains viscacha) has a high rate of embryonic resorption. The cranial and middle implants are reabsorbed 25-35 days after intercourse while the caudal ones continue with their development until they originate two precocial offspring. So far, no uterine studies of empty L. maximus females were performed to determine the possible existence of variations in the organ that could be related to the differential survival of the implants. Through an ultrasonographic, morphological, histometric, histochemical, lectinhistochemical and immunohistochemical study, differences in the uterine glands, vasculature and musculature along the uterine horns, with greater development of the caudal region in all cases were observed. These regional variations could be decisive in explaining the reason why only caudal implantations come to term. In contrast, no differences in the morphology, histochemistry and lectinhistochemistry neither of the luminal and glandular epithelial cells, nor in the expression of cell proliferation and apoptosislabels, and in the hormonal receptors were found. This could be related to the fact that implants occur throughout the entire horn.