Patterns of endothelium-dependent circulation reactions development in patients with ischemic stroke in case of oxigenation disturbances

Aim. To study features of tissue oxygenation and changes in nitroxidergic and endothelinergic mechanisms of circulation regulation in ischemic stroke and hypoxia modeling.

Methods. 74 men and women with ischemic stroke were examined and experimental study on 30 outbred white male rats was conducted. All patients underwent computed tomography of the brain, neurological status was assessed and general clinical examination was performed. Tissue oxygen tension was measured percutaneuosly using polarographic method. Chronic hypoxic hypoxia was simulated in animals by daily 40-50 minutes inhalation of 10% oxygen mixture for 4 weeks. Blood oxygen tension was evaluated in patients and laboratory animals. Nitric oxide level of was assessed by determining its stable metabolites. Endothelin-1 level was determined by ELISA. Data was analyzed using «Statistica 8.0» software using non-parametric tests. Differences were considered as statistically significant at p <0.05.

Results. Disturbances in endothelium-dependent mechanisms of vessels regulation, which were interrelated with oxygen tension changes were registered in patients with ischemic stroke. In laboratory animals amid the chronic hypoxic hypoxia concentration of the nitric oxide and endotheline-1 stabile metabolites increased.

Conclusion. Chronic hypoxic hypoxia causes disturbances in endothelial mechanisms of vascular tone regulation; predominance of vasoconstrictive effects of endothelium results in blood pressure increase, development of tissue hypoxia, contributes to neurologic deficit progression and influences the stroke dynamics in patients with ischemic stroke.