Figure 2. Treatment with the NOS inhibitor L-NAME improves responsiveness to inhaled NO in lungs of LPS-treated rats. Untreated control rats (n = 7) and rats treated with LPS 2 h earlier (n=6) received a bolus injection of L-NAME (7 mg/kg). Fourteen hours after L-NAME administration, the lungs were isolated and perfused. The PAP was increased by 5 mmHg using U46619, and decreases in PAP during ventilation of 0.4, 4, and 40 ppm NO were measured. Early administration of L-NAME improved responsiveness to inhaled NO in lungs from LPS-treated rats (*P < 0.05 values differ when comparing LPS-treated rats with and without L-NAME at each NO level).