[The biochemical properties of L-arginine/nitric oxide pathway in rat brain mitochondria].
Biochemical property of L-arginine (L-Arg)/nitric oxide synthase (NOS)/nitric oxide (NO) system was observed in rat brain mitochondria. The results showed that there existed L-Arg transporters of high-affinity, low-transport and saturability in mitochondria membrane of normal rat brain. The maximum transport velocity (V(max)) and Michaelis constant (Km) were 5.87+/ -0.46 nmol/mg pro x min(-1) and 7.8+/- 0.56 micromol/L respectively. In normal condition, endothelium-type NOS was expressed in the mitochondria of rat brain, with its V(max) and Km being 2.7+/-0.3 nmol/mg pro x min(- 1) and 20.85+/-3.27 micromol/L, respectively. NO production was increased in a time-dependent manner and reached a maximum value at 60 min. These results suggest that the L-Arg transporters in MT membrane of normal rat brain were similar with Y(+) type amino acid transporters in cellullar membrane. Furthermore the NOS of mitochondria belongs to eNOS, whereas the L-Arg/NOS/NO system may be a source of NO.
Cao
J
J
Institute of Cardiovascular Diseases, the First Hospital, Peking University, Beijing 100034.
Wang
L
L
Zhao
B L
BL
Chen
Q T
QT
Qi
Y F
YF
Tang
C S
CS
D000818:Animals; D001120:Arginine / Q000378:metabolism*; D001692:Biological Transport; D001921:Brain / Q000378:metabolism*; D008297:Male; D008928:Mitochondria / Q000201:enzymology*; D009569:Nitric Oxide / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III; D051381:Rats; D017208:Rats, Wistar
D009569:Nitric Oxide; D001120:Arginine; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; C496316:Nos3 protein, rat