Functional immunochemical homeostasis system in stressed animals with different resistance to hypoxia

Objective: to study how original sensitivity to hypoxia influences immunitydependent suppression of microsomal oxidation in stressed and unstressed animals. Materials and methods: we used pressure chamber to model hypoxia. Animals were divided into 3 groups: high-resistant (HR), low-resistant (LR) and medium-resistant (MR) to hypoxia. Then animals with different levels of resistance to hypoxia were exposed to immobilization stress by intraperitoneal administration of ram erythrocytes. 5 days later animals were sacrificed. We estimated content of cytochromes P450 and b5 in liver microsomes and assessed oxidoreductase activity. Findings: high-resistant animals in comparison with low-resistant animals have decreased activity of NADP cytochrome P450 reductase, meanwhile low-resistant animals have increased level of this activity. Immunization combined with previously provoked stress led to decrease in cytochrome P450 concentration in high-resistant animals and, vice versa, to increase of this concentration in low-resistant animals. Conclusion: microsomal oxidation sensitivity to immunization effect depends on original resistance to hypoxia. Resistance to hypoxia also influences modifying effect of previous stress on immunity-dependent changes of microsomal oxidation.