Kinetics of nitrogen oxide production following experimental thermal injury in rats.
Nitric oxide is biosynthesized from the amino acid L-arginine by the enzyme nitric oxide synthase. Nitric oxide is a vasodilator, a neurotransmitter, and may modulate immune function. The experiments presented here were performed to determine whether the synthesis of nitric oxide is increased following experimental burn injury in rats. After a 30% total body surface area burn in 300-g Lewis rats, the urinary output of nitrate, a stable metabolite of nitric oxide, was significantly increased for 8 days postburn compared with that in sham-burned control rats. The origin of the urinary nitrate from L-arginine was demonstrated by administering the stable isotope 15N2-guanido-arginine to burned and sham-burned rats and observing an immediate enrichment of 15N in nitrate. The amount of administered 15N recovered as 15NO3 was < 1% of the administered arginine isotope in both the burned and unburned rats; the recovery of the isotope increased tenfold over baseline recovery in burned rats. The arginine analog N-monomethyl-arginine, an inhibitor of the enzyme nitric oxide synthase, blocked the postburn rise in urinary NO3 output in burned rats, but did not completely inhibit the output of NO3 in burn wound-infected rats. Experimental burn injury in rats results in an increase in L-arginine-dependent nitric oxide production and urinary nitrate output.
Becker
W K
WK
US Army Institute of Surgical Research, Fort Sam Houston, San Antonio, Texas 78234-5012.
Shippee
R L
RL
McManus
A T
AT
Mason
A D
AD
Pruitt
B A
BA
D000818:Animals; D001120:Arginine / Q000378:metabolism; D002056:Burns / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D009566:Nitrates / Q000652:urine; D009569:Nitric Oxide / Q000378:metabolism*; D051381:Rats; D011917:Rats, Inbred Lew; D013997:Time Factors; D014946:Wound Infection / Q000378:metabolism
D009566:Nitrates; D009569:Nitric Oxide; D001120:Arginine