IBIMOL   23987
INSTITUTO DE BIOQUIMICA Y MEDICINA MOLECULAR PROFESOR ALBERTO BOVERIS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Dopamine modifies striatal mitocondrial function.
Autor/es:
CZERNICZYNIEC, A.; BUSTAMANTE, J.; LORES ARNAIZ, S.
Lugar:
Buzios, Brasil
Reunión:
Congreso; I IBRO/LARC Congress of Neurosciences of Latin America, the Caribbean and Iberian Peninsula; 2008
Institución organizadora:
International Brain Research Organization (IBRO)
Resumen:
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 of
respiratory chain. The aim of this work was to determine the in vitro effects of dopamine on striatal
mitochondrial function. Dopamine (DA) and oxidation products have been related to mitochondrial
dysfunction. Striatal submitochondrial membranes and intact mitochondria and were incubated with
different 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 0.5-0.751 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 trhough
inhibition of oxygen consumption, inhibition of cytochrome oxidase activity, increase in hydrogen
peroxide production and mitochondrial membrane depolarization.in vitro effects of dopamine on striatal
mitochondrial function. Dopamine (DA) and oxidation products have been related to mitochondrial
dysfunction. Striatal submitochondrial membranes and intact mitochondria and were incubated with
different 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 0.5-0.751 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 trhough
inhibition of oxygen consumption, inhibition of cytochrome oxidase activity, increase in hydrogen
peroxide production and mitochondrial membrane depolarization.