PTGS2 and obesity due to melanocortin 4 receptor deficiency: To identify the specific COX isoform involved in TRPC5-regulated vascular contraction in obesity, we exposed aortas to the nonselective COX inhibitor indomethacin (1 μmol/L), the COX-1 selective inhibitor VAS-2870 (30 μmol/L), and the COX-2 selective inhibitor NS-398 (3 μmol/L), before ACh stimulation.