EFFECT OF DORSAL ROOT GANGLIA CRYOEXTRACT ON THE STRUCTURAL AND FUNCTIONAL CHARACTERISTICS OF OVARIES IN RATS OF DIFFERENT AGES

Abstract

Goal. The goal was to study the effect of the dorsal root ganglia cryoextract (DRGCE) as a composition containing neurotrophic factors on the structural and functional characteristics of rat ovaries of different ages. Methods. The experiments were performed on female white rats of 6 and 14 months of age that corresponds to the reproductive and late reproductive age of this species of animals. DRGCE was made from dorsal root ganglia of neonatal piglets. Before the DRGCE was used, it was mixed with the physiological saline (PS) so that the concentration of the protein was 0.3 mg/ml. DRGCE was intraperitoneally injected for 9 days (0.2 ml/animal). In the control group, PS was used instead of DRGCE. The injection of DRGCE and PS started in the estrous. To assess the progression of the estrous cycle, vaginal smears were taken daily at 10 a.m. for two weeks before administration, during administration, and for 20 days after administration of DRGCE. The duration of the estrous cycle, relative number of estrous and diestrus phases as well as irregular estrous cycles were studied. 28-29 days after the start of DRGCE administration, animals were killed. Histological analyse of ovarian follicles of different stages of development were carried out. Results. DRGCE administration in rats of reproductive age increased the duration of estrous cycle due to diestrus phase and the number of irregular estrous cycles. Similar changes in the estrous cycle of late reproductive age animals were observed regardless of the administration of DRGCE. The quantitative analysis did not show statistically significant differences between the total numbers of follicles in all animal groups. DRGCE administration led to a decrease the number of primordial follicles and an increase the number of atretic follicles in the ovaries of animals of both reproductive ages. In rats of reproductive age, the number of antral follicles decreased after application of DRGCE. Conclusions. Administration of DRGCE stimulates the growth and development of primordial follicles, but at the same time increases process of follicular atresia, especially at the antral stage. This effect does not depend on the age of the experimental animals.

Keywords

• dorsal root ganglia
• cryoextract
• ovary
• follicles
• estrous cycle
• reproductive age.