Influence of imbalance of thyroid hormones on carbohydrate determinants of ovaries and endometry

The relevance. The structures of the female reproductive system organs are rich in various classes of high molecular weight biopolymers containing a carbohydrate component. Carbohydrate determinants are among the first to be damaged during the development of pathological processes and therefore can serve as early and informative markers of damage to the female reproductive system organs, reproductive function in particular. Sufficiently sensitive and selective markers of carbohydrate determinants of biopolymers are lectins, the use of which as tools for studying the nature of changes in glycoconjugates of organs and tissues in normal conditions and in various forms of pathology continues to be an urgent task. The aim: in an experiment on rats to investigate the effect of hypo- and hyperthyroidism on the carbohydrate determinants of the ovaries and endometrium, using for this purpose a set of lectins of different carbohydrate specificity. Methods. The experiment was carried out on 65 sexually mature female white Wistar rats weighing 200-250 g. All animals were divided into 5 groups: control, hypo- and hyperthyroidism (15 animals in each group), as well as 2 groups with correction of hypothyroidism (10 animals in each group). Carbohydrate determinants of the structures of the endometrium and ovaries were studied using 20 lectins, including 15 conventional ones, as well as 5 new original preparations, purified from representatives of the subkingdom of basidiomycetes fungi. Results. The analysis of the results of the redistribution of lectin receptors against the background of hypo- and hyperthyroidism showed that hyperthyroidism is accompanied by a more pronounced effect on the carbohydrate determinants of ovarian structures compared to the hypothyroid state. However, the latter was characterized by pronounced leukocyte infiltration of the medulla of the ovary, and the most selective histochemical marker was the lectins PNA, SBA, and UDA. According to our research, yellow bodies that were formed in hyperthyroid animals had morphological signs of increased functional activity. In follicular cells, the lack of thyroid hormone resulted in a slight decrease in the number of UDA and PAFA lectin receptors and increased expression of SBA-reactive glycoconjugates in them. In the microstructures of the endometrium of rats with experimental hypothyroidism, in comparison with controls, a reduction of carbohydrate determinants with terminal DGal and DGalNAc residues was found in combination with the accumulation of glycopolymers with terminal LFuc residues. The group of hypothyroid animals was also characterized by an intense reaction of leukocytes with the majority of lectins. In the group of animals with hyperthyroidism, the reactivity of endometrial structures with the vast majority of used lectins increased. This was especially true of thickened and intensely positive collagen fibers. The results of lectin-histochemical studies of endometrial microstructures during the correction of hypothyroidism with replacement doses of thyroxine correlated well with general morphological data: massive leukocyte infiltration of the endometrial stroma decreased to control values when using 30 mg/kg, but not 1.6 mg/kg of thyroxine. The general morphological and lectin-histochemical changes of the endometrium in the case of thyroid hormone imbalance were more pronounced than the response to the modeling of these pathological conditions by ovarian structures. This was manifested, in particular, in increased leukocyte infiltration and increased collagenization of the endometrium.