Kidney mitochondrial nitric oxide synthase.
Nitric oxide synthase activity was recognized in rat renal cortex mitochondria (mtNOS) with nitric oxide (NO) production rates of 0.14-0.78 nmol/min/mg of protein. Rat pretreatment with enalapril (30 mg/kg/day i.p., up to 15 days) increased NO production in kidney, liver, and heart mitochondria. In kidney, mtNOS activity and mtNOS protein, measured by western blot densitometry, were 5 and 2.3 times increased, respectively. Electron paramagnetic resonance analysis with the probe N-methyl-D-glucamine dithiocarbamate/FeSO(4) detected NO production in mitochondria isolated from enalapril-treated rats, but not in control untreated animals. Polyclonal antibodies anti-iNOS and anti-nNOS detected kidney mtNOS in western blots and inhibited mtNOS biochemical activity. The enzymatic activity of kidney mtNOS generates intramitochondrial NO concentrations that regulate mitochondrial functions: state 3 respiration was decreased by 12-28%, and state 4 hydrogen peroxide production was increased 12-35%.
Boveris
Alberto
A
Laboratory of Free Radical Biology, School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina. aboveris@ffyb.uba.ar
Valdez
Laura B
LB
Alvarez
Silvia
S
Zaobornyj
Tamara
T
Boveris
Alejandro D
AD
Navarro
Ana
A
D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D015153:Blotting, Western; D002462:Cell Membrane / Q000378:metabolism; D003580:Cytochromes / Q000032:analysis; D004578:Electron Spin Resonance Spectroscopy; D004656:Enalapril / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000032:analysis / Q000378:metabolism; D007672:Kidney Cortex / Q000201:enzymology* / Q000378:metabolism; D008928:Mitochondria / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D008929:Mitochondria, Heart / Q000187:drug effects / Q000201:enzymology; D008930:Mitochondria, Liver / Q000187:drug effects / Q000201:enzymology; D009569:Nitric Oxide / Q000032:analysis / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051381:Rats; D012119:Respiration / Q000187:drug effects; D015854:Up-Regulation
D000906:Antibodies; D003580:Cytochromes; D009569:Nitric Oxide; D004656:Enalapril; D006861:Hydrogen Peroxide; D019001:Nitric Oxide Synthase