Effects of nanobiomaterial-based antioxidants on testis histomorphology of males under heat stress or diabetes

Male infertility is an urgent problem of veterinary reproductive medicine. According to the latest scientific trends, oxidative stress is the main pathogenetic mechanism of its occurrence. It is known that such common pathological conditions as heat stress and diabetes can lead to disturbances in the functional activity and histoarchitectonics of male gonads. To correct the changes accompanying these conditions, many compounds with antioxidant properties, including nanostructured ones, have been proposed. Therefore, the goal of our research was to substantiate the effect of antioxidant preparations based on nanobiomaterials on the histostructure of the male gonads of domestic animals under the influence of heat stress or the influence of diabetes. Males of two species of animals were chosen for the study: rabbits of the Hyplus breed (n=12) and boars breed line big white × yorkshire (n=10). Animals were randomly divided into two groups: control and experimental. Diabetes was reproduced in rabbits using a commonly used alloxan model, controlling hyperglycaemia biochemically. Boars were kept at elevated environmental temperatures in the summer, showing infertility due to deterioration in the quality of ejaculates. For the correction of antioxidant protection, a research group of boars was given a combined administration of vitamin A and nanoparticles of gadolinium orthovanadate, and for this purpose α-lipoic acid and N-acetylcysteine were given to rabbits. When examining histological sections of the testes of control group animals, typical changes were revealed: most of the tubules were empty. In some animals, spermatogenesis was stopped at the stage of formation of spermatids, which prevented the formation of morphologically complete spermatozoa and, as a result, their complete absence in the lumen of the tubules. The epithelium of tubules was characterized by dystrophic changes. The diameter of the seminiferous tubules was much smaller. Also, the number and size of interstitial endocrinocytes and their nuclei were reduced; polymorphism, a decrease in the oxyphilic properties of the cytoplasm and vacuolation phenomena were observed. During antioxidant correction, restoration of the structure of the testes under heat stress was noted in boars: the diameter of convoluted seminiferous tubules increased by 31.3% (p˂0.05), the presence of mature spermatozoa in the tubules, an increase in the number of interstitial endocrinocytes and their nuclei was noted. The introduction of α-lipoic acid and N-acetylcysteine contributed to the normalization of the morphology of the rabbit’s gonads with alloxan-induced diabetes mellitus, a decrease in interstitial oedema and the presence of signs of preservation of spermatogenesis were observed, some convoluted tubules were restored, which in general led to an increase in their diameter by 37.3 % (p˂0.05).