[Changes in nitric oxide-related compounds in endotoxemic rats]

NO-related compounds in the blood of septic rats were examined by chemiluminescence method. Rats were treated with 5 mg/kg or 10 mg/kg lipopolysaccharides (LPS) and followed for 30 h. We have determined and evaluated the concentrations of the total NO-related compounds in whole blood (Total-NO), those in plasma (Plasma-NO) and membrane bound-NO (Membranous-NO) in erythrocytes from the LPS-challenged rats. 1) Levels of Plasma-NO after 3 h and Membranous-NO after 7 h in the rats were significantly increased, peaked at 14 h, and then restored to control levels at 30 h. 2) At 7 h in the rats, latter NO levels were exhibited within 10 nM/mg protein. 3) The existence of Membranous-NO can be confirmed by the in vitro experiments of rat erythrocytes incubating with different NO-donors, NOC-3 or SIN-1. 4) Taken together, the determination of Membranous-NO may be an additional marker for pathophysiological states of septic stress.