Figure 1.

RENCA cells do not express iNOS protein, despite high mRNA expression levels. RENCA cells (8 × 10⁶) were incubated in serum-free medium with or without IFNγ (100 U/ml) and LPS (1 μg/ml) for 24 hours under either normoxic or hypoxic conditions. A: A representative gel showing that Western blot analysis could not detect iNOS protein expression (n = 4). N, normoxia; H, hypoxia; PC, positive control (RAW 264.7 cell lysate). B: Determination of nitrite concentrations in the supernatants (n = 5). C: Accumulation of iNOS mRNA in RENCA cells after a 24-hour incubation in normoxic conditions with or without the addition of IFNγ and LPS as determined by real-time PCR, normalized to the endogenous reference gene PBGD, and calibrated to non-stimulated cells (n = 5). *P < 0.05 relative to no stimulation; ^†P < 0.05 relative to stimulated RENCA cells in normoxic conditions.