Dopamine modifies striatal mitocondrial function.

CZERNICZYNIEC, A.; BUSTAMANTE, J.; LORES ARNAIZ, S.

Buzios

Congreso; I IBRO/LARC Congress of Neurosciences of Latin America, the Caribbean and Iberian Peninsula; 2008

Dopamine (DA) is able to induce neurotoxic effects in several neurological and psychiatrics diseases. It has been postulated that dopamine may generate changes on mitochondrial function by inhibition ofrespiratory chain. The aim of this work was to determine the in vitro effects of dopamine on striatalmitochondrial function. Dopamine (DA) and oxidation products have been related to mitochondrialdysfunction. Striatal submitochondrial membranes and intact mitochondria and were incubated withdifferent DA concentrations for 5 minutes. Significant changes were observed in state 4 oxygen uptake (resting respiration) after 1 mM dopamine incubation. A 35% decrease in state 3 oxygen uptake (active respiration state) was found after 1 mM dopamine incubation. Incubation of submitochondrial membranes with 0.5-0.75–1 mM dopamine inhibited cytochrome oxidase by 38%, 46% and 53% respectively showing the possible inhibition or mitochondrial respiration through the inhibition of cytochrome oxidase. Complex I activity was significantly inhibited by incubation of striatal submitocohondrial membranes with 1 mM dopamine. Hydrogen peroxide production significantly increased by 91% 1 mM DA incubation. Also, DA was able to induce striatal mitochondrial membrane depolarization.Our results suggest that in our study conditions, DA modifies striatal mitochondrial function trhoughinhibition of oxygen consumption, inhibition of cytochrome oxidase activity, increase in hydrogenperoxide production and mitochondrial membrane depolarization.