Medicine/8.Morphology

Ulyanov V.O.

Odessa State Medical University, Odessa, Ukraine

The structure of ovaries in posterity of the irradiated rats

 

Radiation induced damages of genome can be realized phenotypicaly in the next generations of the irradiated people and animals. However the state of parenchima and stroma of ovaries in descendants of irradiated mammals wasn’t investigated enough. Dependence between the degree of ovary tissue damaging and amount of pathological changes of gametes and pregnancy process wasn’t established.

Purpose of work: to study the morphological changes in ovaries of posterity of the irradiated rats in postnatal ontogenesis.

The rats of experimental lines Wistar of 3-4 month-old were researched. Animals were divided into two groups: 1) intact unpregnant females (n=21); 2) unpregnant females of posterity of the irradiated rats (n=21).

The males and females of rats were irradiated by fractional g- irradiation every 72 hours for 0,1 Gy for a session to achieving a total dose 1,0 Gy. Animals were coupled after completion of the irradiation. Animals were destroyed from the experiment on 14, 30 and 90 days of ontogenesis. Ovaries were removed. It was prepared permanent histological preparations which were painted by hematoxylin-eosin and be van Gysoni.

         It was established that in 14-daily females of posterity of the irradiated rats, the structure of ovaries had expressive enough differences comparatively with control. The amount of follicles on the plane of section was more than in control group. The follicles were densely located in a cortical substance. The cortical substance prevailed over the medullar substance, but degree of its maturity was smaller. An interstitium was developed weaker. The follicles were heterogeneous: some parts had a normal kind; other parts were with the signs of destruction. The nucleuses in a lot of follicular cells were in the state of karyopicnos and karyorrhexis. It was set as apoptotic little bodies so mitosis. A theca was well developed and was presented as densely located light cells, considerably larger than follicular cells. The ovocytes were without features, hadn’t differences with the norm. An effect of atresia was absent. The vessels of the medullar substance were densely located. They were thin-walled with blood cells inside.

         In the 1-month-old posterity of the irradiated rats the general view of ovaries very looks like the previous term of research (2 weeks). An ovary had a lot of follicles, but the secondary and thirdary follicles prevailed. The interstitium layers were thicker, than in control group. At supervision above follicles there was the impression that proliferative processes left behind the ripening of follicles. The well-shaped follicles with normal ovocytes and well developed transparent and granular membrane were not enough. The cavities of follicles were undeveloped, often were absent, without regard to a thick granular area. It is possible to assume that the secretion of liquid, rich on estrogens, was broken or absent. Follicular epithelium was with the signs of karyorrhexis, destruction and apoptosis. The normally formed atretic bodies were absent. There were large follicles in which a theca was well formed with the differentiated layers. There were some areas of dilution within the limits of granular layer.

The interstitium was edematous comparatively with 2 weeks of experience. There were cells with high functional activity around the follicles in the interstitium. They were sharply selected between typical cells. They located single. They were more light and large than circumferential cells. Its cytoplasm was heterogeneous. The nucleuses were very large, sometimes eccentric with well expressed chromatin. The structure of these cells was like as glandular cells. The appearance of these cells with hypertrophic thecacytes was a compensatory reaction to decreasing of endocrine function of follicle cells.

         The ovaries of 3-mont-old posterity of the irradiated rats looked like less functionally active organs, comparatively with control. The amount of ripening follicles on the plane of section was decreased. An effect of atresia was more expressive. At the same time, fully formed functionally active atretic bodies weren’t enough.

         Conclusions. The g-irradiation of male and female rats before a coupling causes violation of forming of ovaries tissue in postnatal ontogenesis of their first generation posterity. It shows up the delay of becoming of connective tissue stroma and changes of cellular cycle of follicle epithelial cells.