Real-time PCR expression of guinea pig mRNA for COX-1, COX-2, mPGES-1, mPGES-2, cPGES and EP1–4 in airway smooth muscle (A, E and I), airway epithelium (B, F and J), lung parenchyma (C, G and K) and aorta (D, H and L). All values are represented as mean ± SEM (n ≥ 5) mol in relation to 105 mol β-actin *, P < 0.05; **, P < 0.01; ***, P < 0.001 denotes significance between selected groups.