The role of vascular injury within the conditions of choline deficiency in rats with scopolamine-induced alzheimer's type dementia

Abstract

Background. The relationship between choline deficiency and vascular dysfunction continues to be relevant in the study of Alzheimer's disease. Objective. To study the morphological characteristics of vascular injury within the conditions of choline deficiency in rats with scopolamine-induced Alzheimer's type dementia. Methods. The experiment was performed on 48 WAG population male rats weighing 180-230 gr. Rats from groups Scop-14, Scop-14-SC, Scop-28, Scop-28-SC were injected intraperitoneally with scopolamine (Scop) butylbromide at a dosage of 1 mg/kg of body mass during 14 and 28 days and intravenously with mesenchymal stem cells (SC) at a single dosage of 500000 cells per 1 rat. Control animals (gr.C) were injected with 0.9% sodium chloride. Brain slides were stained with Congo-red and gallocyanine-chromium alum according to Einarson's method for total nucleic acids. The VEGF, E-cadherin expression was immunohistochemically determined in the brain cells cytoplasm. Results. The congophilic staining of the arteries walls, a decrease in endothelial cells with low the E-cadherin expression and an increase in the number of pericytes in the capillary wall was observed in the experimental groups. In gr.Scop-28 VEGF expression in endothelial cells, hippocampal neurons was greater than in gr.Scop-14. It indicated more intensive activation of angiogenesis and acetylcholine synthesis with correspondingly more pronounced vascular damage and choline deficiency. The cytoplasm of cortical neurons was diffusely labeled with VEGF antibodies in response to hypoxia, but the level of expression was almost no different from that in gr.C. In all groups, the optical density of the neuropile of the large hemispheres according to Einarson’s staining was reduced, i.e., the level of RNA in the neuronal processes was reduced. The introduction of stem cells restored the capillary wall due to young endothelial cells, reduced the VEFG synthesis in all studied cells and increased the RNA content in neuronal processes. Conclusion. The relationship between choline deficiency, neuronal process loss and vascular damage has been found. The blood vessels self-repair was occurred by substitution, after the stem cells introduction - by restitution.