Ester Loncoñanco; Felipe Navarrete; Nicolás Cuevas; Adriana Vasconcellos & Marco Paredes

Progesterone receptors are expressed in the reproductive organs of adult sheep, where they regulate morphofunctional and reproductive development. However, various studies have shown the presence of these receptors in the uterus of prepubertal females. It is not clear what role these receptors have at this level of development in uterine tissue. Therefore, it is relevant as a first step in the investigation, to determine the expression and histological distribution of the progesterone receptor in prepubertal sheep in order to determine possible functions at this level of reproductive development. Immunohistochemical analysis allows visualizing the specific presence of a protein in the cellular and histological context, however, the results displayed through digital images are qualitative data and subject to the observer's criteria. In this work, a quantitative analysis method of immunohistochemical expression of the progesterone receptor in ovine endometrium is presented, using digital analysis of images, by means of integrated optical density of digital photographs of histological sections processed with immunohistochemical methods. The results show the possibility of quantitatively evaluating the expression of progesterone receptors in the endometrial stroma and prepubertal endometrial glands by applying the integrated optical density analysis of digital images.

KEY WORDS: Sheep reproductive development; Araucana sheep; Integrated optical density.

LONCOÑANCO, E.; NAVARRETE, F.; CUEVAS, N.; VASCONCELLOS, A. & PAREDES, M. Integrated optical density analysis of the immunohistochemical expression of the progesterone receptor in the uterine endometrium of prepubertal Araucana sheep. Int. J. Morphol., 39(5):1278-1282, 2021.