Stereological and functional study on ovarian follicles in surri mice following soybean consumption

Soybean is a plant known as Glycine max that due to its essential amino acids and isoflavones which are amongst the most important types of phytoestrogens is widely used. The function of ovary is directly affected by serum levels of the hormones estrogen and progesterone. The objective was to evaluate the morphometric characteristics of the ovaries followed by consumption of soybean through the precise and non-convergent technique of stereology, in immature animals. Thirty adult NMRI female mice at the age of 3 weeks were divided into three groups including the control, the experimental 1, and the experimental 2. The animals were fed a diet prepared by a nutritionist for 3 months. The control group received a soy-free diet and the experimental groups 1 and 2 received a diet that provided 15 and 35% of soybean as the protein content, respectively. Serum levels of the hormones estrogen, progesterone, FSH, and LH were measured and the right ovaries were used for stereological studies. The results showed a significant increase in the volume of pre-antral and antral follicles, the ratio of cortical volume to total ovarian volume, the ratio of corpus luteum volume to total ovarian volume, the ratio of the total volume of follicles to the total volume of ovaries, and also the volume of oocytes in follicles (P < 0.05). Also in treatment groups, between serum levels of estrogen and progesterone, a significant increase was observed. The present study showed that soybean meal consumption affects the morphometric characteristics of the ovaries.