CHARACTERISTICS OF CYTOPROTECTIVE EFFECT ON THE GASTRIC MUCOSA OF CRYOPRESERVED PLACENTA EXTRACT UNDER WATER-IMMOBILIZATION STRESS

Abstract

Various stressors are currently considered to play a significant role among the etiological factors for development of peptic ulcer disease. Along with psycho-emotional stressing experiences, the causes of formation of stress ulcers include major surgical interventions, thermal or mechanical injuries, severe blood loss, progressive syndrome of endogenous intoxication and more. Among patients in intensive care units, the incidence of stress ulcers is 5.0%, and in 30.0-50.0% of cases stress ulcers are complicated by bleeding and perforation. Aim. The research aims at characterizing the gastrocytoprotective effect of cryopreserved placenta extract (CEP) on the model of water-immobilization stress in rats according to macroscopic data and the results of biochemical study of homogenates of the gastric mucosa (GM). Materials and Methods. In vivo experimental studies were performed on 28 nonlinear laboratory male rats weighing 200-220 g. Stress-induced gastric ulcer was simulated under water-immobilization stress (WIS) in rats. WIS simulation according to the method of Takagi K.Y. et al. The activity of NO synthases (NOS) in GM was determined spectrophotometrically by the amount of oxidized NADPH+H+. Results and Discussion. The use of CEP, as well as esomeprazole, led to a weakening of GM ulcers. This was indicated by a statistically significant (p<0.05) decrease in ulcer index (UI) relative to the indicators of control rats by 9.8 and 3.3 times, respectively. At the same time, this indicator was three times lower on the background of preventive use of CEP than in rats treated with esomeprazole, respectively, antiulcer activity (AUA) was 96.4% and 69.2%. The study of the activity of constitutive (cNOS) and inducible (iNOS) isoforms of NOS showed that at the pathobiochemical level against the background of stress-induced ulcerogenesis in the tissues of the central nervous system there is a statistically significant (p<0.001) increase in iNOS activity in 5.2 times was 0.89±0.01 NADPH2/min´g protein. According to the degree of modulation of the activity of both total NOS and its individual isoforms, the study showed that preventive five-day administration of esomeprazole is inferior to the effectiveness of CEP. Thus, the activity of total NOS in rats administered esomeprazole was statistically significantly (p<0.001) decreased by only 17.1%, while the activity of this enzyme decreased (p<0.001) by 35.8% due to the use of CEP. Conclusions. Prophylactic five-day administration of CEP modulated the activity of the NOS system in the central nervous system, which in a macroscopic study appeared statistically significant (p<0.05) reduction in UI relative to rats in the control group by 9.8 times. Thus, NOS activity statistically significantly (p<0.001) decreased by 35.8%, and iNOS activity statistically significantly (p<0.001) decreased by 58.4% relative to the control animals. CEP under the prophylactic regimen showed more pronounced anti-ulcer activity than esomeprazole, which was 96.4% and 69.2%, respectively.