Changes in tissue level of nitrite and nitrate (NOx) in the heart, lung or aorta at 1 or 4 h after systemic injection of LPS (15 mg/kg) or saline in rats that were maintained under propofol anesthesia (15 or 30 mg/kg/h). Values are mean ± SEM of quadruplicate analyses of samples from 4 animals per each experimental group. *P < 0.05 vs. saline group and #P < 0.05 vs. low dose (15 m/kg/h) propofol group at corresponding time points in the Scheffé multiple-range test. Basal indicates NOx content in the corresponding tissue prior to LPS injection. The same data prior to saline injection was not shown because they were similar to that of LPS groups.