Accumulation of D-arginine by rat liver mitochondria.
The permeability of the inner mitochondrial membrane from rat liver to D-arginine was studied. By using safranin as a probe of the membrane potential, depolarization of energized liver mitochondria occurred in a dose-dependent fashion starting at 3.3 mmol/L of D- or DL-arginine. When ethidium bromide fluorescence was employed, a decrease in the membrane potential due to D- or DL-arginine was observed. A parallel significant change in succinate-induced respiration in rat liver mitochondria was found in response to osmotic swelling in 125 mmol/L of D-arginine salts. L-Arginine, L-glutamine, L-asparagine, L-ornithine, D-ornithine, and L-lysine did not modify the membrane potential at the concentrations tested. D-Arginine was not transformed into citrulline, but 1.0 mmol/L of the D-amino acid inhibited, by 42%, the state 3 of mitochondrial respiration using succinate as substrate. When D-arginine was used in combination with nigericin, a 40% inhibition of mitochondrial respiration in state 3 was recorded with succinate and with glutamate-malate as substrates.
Villalobos-Molina
R
R
Departmento de Bioquimica, Facultad de Medicina, Universitad Nacional Autónona de México.
Pardo
J P
JP
Saavedra-Molina
A
A
Piña
E
E
D000596:Amino Acids / Q000494:pharmacology; D000818:Animals; D001120:Arginine / Q000378:metabolism*; D002956:Citrulline / Q000096:biosynthesis; D007425:Intracellular Membranes / Q000378:metabolism*; D008297:Male; D008564:Membrane Potentials; D008930:Mitochondria, Liver / Q000378:metabolism*; D009997:Osmotic Pressure; D010101:Oxygen Consumption; D010539:Permeability; D051381:Rats; D011919:Rats, Inbred Strains
D000596:Amino Acids; D002956:Citrulline; D001120:Arginine