Alternative splicing of cyclooxygenase-1 mRNA in the human iris.

In homogenates of the human iris, the nonsteroidal anti-inflammatory drug (NSAID) S(+)flurbiprofen has been reported to inhibit cyclooxygenase-1 (COX-1) 70-fold more potently than in human whole blood. We hypothesized that this difference may be due to alternative splicing of COX-1 mRNA in the human iris or in whole blood. In this study, we have identified a similar COX-1 splice variant (COX-1SV) in both tissues with comparable COX-1/COX-1SV expression ratios. Therefore, we conclude that the difference in IC(50) values of S(+)flurbiprofen towards COX-1 in the human iris and human whole blood is not related to differences in the occurrence of spliced COX-1.