Influence of hypoxia on the release of DA from striatal preparations of rats

The effects of hypoxia in adult and newborn rats on the release rate of DA from slices and synaptosomes of striatum were studied. In adult animals hypoxia (10 kPa oxygen tension in the inspiratory air) induces a decrease of the FER of DA from slices up to 70% dependent on the duration of the hypoxia. An early postnatal hypoxia (10 kPa, 2nd -11th day of life) brings about a long-term increase of the FER of DA from slices by about 30% when the release is measured at the age of 2-3 month. Slices show a relatively low release rate compared to synaptosomes. The hypoxia effects found with slices, i.e. a decrease of the FER in adult animals and increase in those that had experienced an early postnatal hypoxia, could not be confirmed in synaptosomes. The much lower release rate from slices suggests the action of inhibitory factors controlling the release of DA. In that case hypoxia would exert an indirect influence.