[The production and deposition of nitric oxide during adaptation to hypoxia]

It is common knowledge that adaptation to hypobaric hypoxia provides for a number of protective NO-dependent effects in the organism. However, many aspects of its influence on NO metabolism remain unclear. In this work we studied the relationship between NO production and deposition in the course of adaptation to hypoxia. No production was assayed by the total concentration of nitrates and nitrites in rat serum, while the volume of NO depot was determined from the level of isolated aorta relaxation in response to diethyldithiocarbamate in vitro. In the course of adaptation to hypoxia, nitrate and nitrite concentration increases as well as NO deposition in the vascular wall. The volume of NO depot correlated reliably with the serum concentration of nitrates and nitrites. Hence, adaptation to hypoxia increases NO production and deposition, which can underlie its NO-dependent protective effects.