Modeling of chronic ovary inflammation

Abstract

In our country preservation of the population reproductive health is a high-priority direction of modern medicine. In many cases, the cause of reproductive disorders in women is a chronic infectious inflammation of the small pelvis, the frequency of which in recent years had no tendency to decrease. The choice of inactivated vaccine of Staphylococcus aureus as a phlogogen was due to the fact that the etiological role of the aerobic infection remains the leading one in gynecological pathology.

The aim of research was studying of the ability to use the inactivated vaccine of Staphylococcus aureus strain 209 for modeling of chronic inflammation of the ovaries in laboratory mice.

Materials and methods. 25 mature outbred white female mice weighing 18-20 g were used as experimental animals, which formed next groups: 1) control (n=5) – animals without any interventions and 2) experimental (n=20) – animals with one-fold intraperitoneal injection of inactivated Staphylococcus aureus strain 209 vaccine in the dose of 50х10⁶ microbial bodies in 0,3 ml of physiological solution. Efficiency of the modeling pathology was performed by histomorphometric and hematological methods on the 7th, 14th, 21st and 31st days. All the manipulations with animals were carried out in accordance to the requirements of bioethics and the international principles of the European Convention for the protection of vertebrate animals. For statistical study ANOVA and t-Student tests were used with application of Microsoft Excel Program.

Results. In the group of control animals the form and histological structure of ovaries were regular for mature mice without signs of inflammatory changes. The leukocyte infiltration, hemodynamic disorders and minor dystrophic changes of granulosa cells were determined on the 7th day in the ovaries of experimental animals. The increasing of observation period up to 14 days on the background of hemodynamic disorders resulted in the appearance of degenerative follicles, atresia of which proceeded by the type of the productive process with the formation of multilayer granulose tunica. The increase in the atretic follicles number, the migration of macrophages in their cavity and disorganization of follicular epithelium cells were determined on the 21st day after the vaccine injection. The proliferation of connective tissue was noted under the basement membrane of the follicles, between generative elements and ovarian medulla. To the 31st day of modeling granulosa cell layers lost ordered structure, reflected in the increasing of intercellular space and accumulation of fluid between the cells.

During the first 14 days after the vaccine the leukocyte number in peripheral blood increased by 3,2 times. However, on the 21st day investigated index was 1,75 times lower in comparison with the previous period (P<0,05). Further, the leukocyte level was not statistically changed (P<0,05), but did not reach values of intact animals (P<0,05), indicating the reduction of the inflammatory process severity.

At the same time there was a statistically significant (P<0,05) reduction in the number of follicles that was probably due to the intensification of processes of atresia. Due to their progression on the 31st day after vaccine injection, the number of follicles in the studied preparations decreased by 1,7 times (10,55±2,48) relatively to the index of control animals (18,25±4,52).

The conclusions. Intraperitoneal injection of inactivated Staphylococcus aureus strain 209 vaccine to the 21st day leads to the formation of chronic inflammation of the ovaries in laboratory mice, which was characterized by the prevalence of atresia processes over follicle growth with the development of sclerotic changes and decreasing of their total number. At the initial time leukocytosis was observed in the blood of experimental animals, and starting from the 21st day inflammation acquired signs of chronic process, which manifested in reducing of number of cells without the normalization of this index until the end of the experiment.