Recurrent hypoglycemia and the structure of the choroid plexus of the lateral ventricles of the rat brain

BACKGROUND. Recurrent hypoglycemia occurs during insulin therapy in patients with diabetes mellitus and is a significant cause of brain dysfunction in these patients. The functioning of the hematocerebrospinal fluid barrier and the production of cerebrospinal fluid (CSF) are of great importance in ensuring brain activity. The main volume of CSF is formed by the choroid plexus of the lateral ventricles (LV) of the brain and the glymphatic system of the brain. The role of the choroid plexus in the development of brain dysfunction in hypoglycemia has not been sufficiently studied.

OBJECTIVE. The aim of this work was to determine the structure of the choroid plexuses of the lateral ventricles of the brain during recurrent hypoglycemia.

MATERIALS AND METHODS. The object of the study were rats that had undergone 9 hypoglycemic states after insulin administration (with an interval of 3 days, the blood glucose level of 1.4–1.8 mmol/L) and intact animals. The volume of the LV and volume fractions of the choroid plexuses in the LV were estimated: the relative volume and total fraction of vessels, fractions of cells and connective tissue. Morphological changes in the epithelium of the choroid plexus and nervous tissue of the periventricular spaces were also recorded.

RESULTS. In animals that had undergone a series of hypoglycemias, the maximum cross-sectional area of the LV, the relative volume of the choroid plexuses of the LV and the volume fraction of vessels per volume of the choroid plexus of the LV increase. The volume fraction of cells per volume of the choroid plexus of the ventricles decreases in rats with recurrent hypoglycemia. Morphological examination of these animals reveals dystrophic changes in the epithelial cells of the choroid plexus and zones of dystrophic changes in the brain tissue surrounding the ventricles.

CONCLUSION. Thus, recurrent hypoglycemia leads to an increase in the maximum cross-sectional area of the LV and the relative volume of the choroid plexuses, as well as dystrophic changes in the epithelial cells of the choroid plexuses and neurons of the periventricular spaces. Since hypoglycemia is repeatedly observed during the treatment of patients with diabetes mellitus, the identified changes may cause cognitive impairment and the development of dementia in these patients.

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