Hypoxia and the metabolic behavior of the immature brain.

The immature brain, affected by hypoxia (of certain degree and duration) shows several distinct differences as compared with the mature one. We demonstrated that previous hypoxia does not disturb the aerobic metabolism (in the newborns). The respiratory rate remains the same or its increase is accompanied by the improved coupling processes (the effect of DNP, increased incorporation of P32 into ATP fraction). Hypoxia elevates--at the same time--in the brain tissue of the youngest rats, the proportion of polyenoic n-3 fatty acids. This mechanism (hydrogen sink effect or hydrogen is drained to the synthetic work-elongation of fatty acids) could be decisive factor explaining the high resistance of the mammalian newborns against any lack of oxygen and at the same time their higher capacity for the recovery processes. This fact acquires a further physiological dimension.