[Changes in the adenosinetriphosphatase activity in plasma membranes incubated in vitro in the presence of 4-hydroxy-2,3-nonenal].

Cation-dependent ATPase activities of rat liver plasmamembranes incubated "in vitro" with 4-hidroxy-2,3-nonenal (HNE, an aldehyde from peroxidative decomposition of biological membrane lipid moieties) are investigated. Mg++-ATPase activity is inhibited significantly by all the doses of HNE used (13,9, 4,1,1,2, 0,35 and 0,10 microM). Evidences for the inhibition of Mg++- Na+- K+- ATPase activity are also presented. Ca++- ATPase activity is strongly increased when rat liver plasmamembranes are incubated in presence of HNE 13,9 microM. Our results suggest that HNE may play a role in the control of intracellular cation levels acting directly on mechanisms of plasmamembranes ion transport.