Гістологічне дослідження яєчників сукрольних кролиць

Abstract

The objective of our experiment was to study the histrostructural changes in the ovaries of pregnant rabbits with previous reproductive cycles in artificial insemination without using further hormonal treatment to increase the reproductive function of rabbits. We have studied the ovaries of pregnant rabbits of the Hyla breed on the 7th day of pregnancy age, which were in the fifth reproductive cycle. The AI technique in rabbits needs an ovulation stimulator or inducer because female rabbits are induced ovulators. In our experiments, we used Surfagon for induction of ovulation by the method proposed by Lisin V. I., Sushko A.B., Institute of animal’s science of the NAAS. The ovaries were fixed in 10%-neutral formalin solution. Paraffin histosections were made and coloured with hematoxylin and eosin according to the standard technique. The macroscopic and microscopic studies of the rabbit ovary of the 5th reproductive cycles indicate a high level of their luteinization. The results of the histological study show that the histostructural picture of the ovaries of pregnant rabbits reflects the nature of the course of the phases of the previous reproductive cycles typical for this animal species. In the ovary of pregnant rabbits of the fifth reproductive cycle, all generations of follicles were found. The predominant functional elements of the ovarian parenchyma were luteal structures: the corpus luteum of pregnancy, atretic bodies and interstitial glandular tissue. There were two types of follicular atresia: obliterating, which took place in the preantral (primary and secondary) follicles and cystic and the antral tertiary follicles. The formation of hemorrhagic follicles was a type of cystic atresia. The formation of atretic bodies occurred as a result of luteinization of primary and secondary follicles. In the ovaries of pregnant rabbits of the fifth reproductive cycle, yellow bodies of various generations were found, that is the evidence of their functioning for several reproductive cycles. The number and development of corpus luteum in the right and left ovaries was asynchronous, which indicates the asynchronous nature of ovulation in the preceding and current reproductive cycles. Interstitial glandular tissue was the predominant histological element in the ovaries of rabbits of the fifth reproductive cycle. Compared with the ovaries of other mammalian species, it was found not only in the cortical, but also in the medulla of the ovaries of pregnant rabbits.