CHANGES IN THE EXPRESSION OF THE AROMATASE AND SUPEROVULATORY RESPONSE IN MICE TREATED WITH THE FEED ADDITIVE PROVIT E10 SUPER

A. SHIMKINE, D. ABADJIEVA, E. KISTANOVA, A. SHUMKIS, V. MLADENOVA

Abstract: The success rate of superovulation procedure is crucial for the embryo transfer biotechnology, applied to the preservation of the genetic resources. The aim of the present study was to track the changes in superovulatory response and the expression of the aromatase in the ovaries of mice treated with the supplement Provit E10% Super. The experiment was conducted in vivarium of the Institute of Biology and Immunology of Reproduction, Bulgarian Academy of Sciences with 30 female laboratory mice, separated and leveled by weight into three groups (n = 10): control group, first experimental group, stimulated by standard protocol for superovulation and second experimental group, in which an effect of superovulation was combined with the individual intake of the supplement for 30 days before hormonal treatment. The methodology included an evaluation of success rate of superovulation, through extraction of the ovulated oocytes from the ampoule of the oviduct. Histological examination of an ovary was carried out on 5 μm paraffin slices stained with H & E by routine method. Aromatase expression was estimated by immunochistochemical method using antibody agains CYP19. Preparations were examined and documented by microscope system Olympus BX 51 (Japan). The results showed that treatment of mice with supplement before superovulation exerts an effect on the folliculogenesis and improves cumulus expansion that reflects on the number of the ovulated oocytes. A more active expression of the enzyme aromatase in the theca cells of preantral and antral follicles in both treated groups compared to the control was observed. For the first time the positive immunostaining of the aromatase in the mice oocytes was found. Stronger immunochemical reaction of aromatase was observed in the corpora lutea of the mice, received the feed additive. In conclusion, supplementing of the Provit E10% Super before hormonal treatment affects the folliculogenesis activity and could be considered as an improvement of the superovulation protocol for the laboratory animals as well as for other species.

Keywords: aromatase; feed additive; immunohistochemistry; mice; superovulation

Date published: 2017-04-28