Induction of PGHS-2 and NOS-2. Following isolation of primary rat alveolar macrophages, the cells were allowed to rest for 24 h to avoid baseline induction of PGHS-2 and NOS-2 that were under detection limit on the mRNA and protein level following this regiment. The cells were then stimulated with LPS (10 μg/ml) for the time periods as indicated. (A) For the mRNA expression analysis, GAPDH served as control, values at t=0 were defined as 1. (B) Protein expression of PGHS-2, NOS-2, and TxA2 synthase was quantitatively assessed, actin served as the loading control. Data represent mean values±SD of at least three independent experiments. *p<0.05 versus t=0. GAPDH, glyceraldehyde 3-phosphate dehydrogenase; TxA2, thromboxane A2.