| Popis: |
The blood of rats with initially low (LR) and high (HR) resistance to hypoxia was characterized with respect to the levels of testosterone, corticosterone, insulin and the activity of liver monooxygenase system enzymes. In response to the acute hypoxia model induction, the level of corticosterone in LR rats was significantly greater than that in HP rats (179 and 24%, respectively). The increase in the blood corticosterone level was accompanied by an increase in the activity of enzymes involved in the metabolism of xenobiotics. Animals with the high corticosterone level were also characterized by more intensive metabolism of testosterone and erythromycine. The metabolism of these substrates depends on the activity of isoforms of the cytochrome P-450 3A family. The high corticosterone concentrations in the plasma of LR rats, appearing in response to the acute hypoxia, exhibit a pronounced stimulating action upon the enzyme 11 beta-hydroxysteroiddehydrogenase, which is accompanied by a more pronounced increase in the corticosterone concentration in liver tissues as compared to that in HR animals. The higher content of corticosterone in LR rats leads to an increase in the concentration of cytochrome P-450 and stimulates the enzymatic activity of 3A isoforms in the liver tissues. |
