Objective. The aim of this study was to assess the vascular endothelium morphofunctional state of the brain microcirculatory bed in rats with nitrite-induced Alzheimer's type dementia on the background of stem cells administration. Methods. 14 days after the experiment's end, the endothelin-1, VEGF-A, eNOS, von Willebrand factor were determined in blood serum by the enzyme immunoassay and photometric methods in rats with a model of nitrite-induced dementia (14 and 28 days of sodium nitrite intraperitoneal introduction) with and without mesenchymal stem cells (MSCs) administration. The brain slices were stained according to the Einarson's method and immunohistochemically by staging the reaction with antibodies to VEGF. Results. With an increase in the sodium nitrite administration period, the degree of damage of brain capillaries and neurons increased, dystrophy of "surviving" neurons developed and ability to produce VEGF decreased. After 14 days of "regeneration period" in groups without MSCs administration, further stimulation of VEGF production by endotheliocytes, cortex and hippocampus neurons of varying degrees was observed. In groups where stem cells were introduced, the number of capillaries increased, with endothelial hyperplasia in some cases. Conclusion. In animals with nitrite-induced dementia, dose-dependent damage to the endothelium of the capillary bed is noted. From the first day damage the vascular regeneration can be proved by VEGF expression. The stem cells administration more effectively stimulates capillary regeneration, as evidenced by a noticeable increase of the number of brain capillaries.
На моделі хронічного стресу спричиненого довготривалою іммобілізацією щурів-самиць в період вагітності, встановлено, що у тканині підшлункової залози і сироватці крові не тільки їх самих, а й їх одно- та двохмісячного потомства відзначається зсув основних показників оксидантно-антиоксидантного гомеостазу, що, можливо є результатом реалізації нейрогуморальної відповіді організму на стрес. Ці зміни не є ідентичними у сироватці крові і тканині підшлункової залози тварин, а інформативність показників оксидантно-антиоксидантного гомеостазу сироватки крові, що використовується для кращого розуміння аналогічних змін в тканині підшлункової залози, є відносною.
The cerebral hemispheres neuropil of rats with experimental nitrite-induced Alzheimer’s type dementia was studied after mesenchymal stem cells (MSC) introduction. Rats were injected with an aqueous solution of sodium nitrite (50 mg/ kg) for 14 (group 1) and 28 days (group 3), and half of them additionally got intravenously MSC (500000 cells per rat) (groups 2 and 4). The control group received saline in the same way. The acetylcholine level, TBA-active substances contents, catalase and superoxide dismutase activities in brain homogenates, and the content of 2,3-diphofoglycerate (2,3- DFG) in erythrocytes were measured spectrophotometrically. Brain slices were stained with Congo red and according to the Einarson method. They were then examined on an Axiostar plus binocular microscope (“Zeiss”, Germany). The optical density of the cerebral hemispheres neuropil had been measured. In all experimental groups, an increase in the content of 2,3-DFG in erythrocytes and an imbalance in the pro- and antioxidant system, oxidative stress development in brain were observed. The neuropil structure of the cerebral hemispheres was changed: we observed focal zones of neurofilaments degeneration and atrophy and amyloid accumulation, especially in group 3. The optical density of neuropil was reduced; this was accompanied by a decrease in the content of acetylcholine. MSC injections resulted in a significant increase in the content of acetylcholine, decrease in the brain oxygen demand and the content of TBA-active substances. Consequently, prolonged sodium nitrite administration leads to the cerebral hemispheres neuropil structure and functional injury. MSC introduction contributes to the improvement of the neuropil morphofunctional state.
The role of the imbalance of regulatory cytokines in the blood of rats under conditions of chronic immobilization stress, compared with the control, in the implementation of immune mechanisms of pancreatic damage was considered, where it was established:
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.