(a) Western blotting of prostacyclin synthase in HMC. Cell lysates (80 μg) of cytokine treated HMC or control were stained with a polyclonal antibody for PGIS. Lane 1: control; lane 2: cytokine stimulation; lane 3: positive control (partially purified protein of bovine PGIS with a molecular mass of 52 KD); lane 4: molecular marker. (b) mRNA analysis of prostanoid generating enzymes and iNOS in HMC. RT-PCR analysis of the mRNA for COX1, COX2, TXS, PGIS, and iNOS from quiescent human mesangial cells (2 × 106) was treated for 20 h with cytokines or vehicle. RNA preparation and PCR analysis were performed as described in Material and Methods. A 100 bp ladder is given on the right to evaluate the mass of the amplified fragments.