Omeprazole-induced relaxation in rat aorta is partly dependent on endothelium

Kelicen P., Pekiner C., Sarioglu Y., Uma S.

PHARMACOLOGICAL RESEARCH, vol.46, no.4, pp.321-323, 2002 (SCI-Expanded) identifier identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 46 Issue: 4
  • Publication Date: 2002
  • Doi Number: 10.1016/s1043-6618(02)00124-x
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.321-323
  • Hacettepe University Affiliated: Yes


We investigated the effect of omeprazole (1 x 10(-5) -3 x 10(-4) M), an inhibitor of H+,K+-ATPase, on rat aortic rings pre-contracted with phenylephrine (10(-6) M). Omeprazole relaxed the tissue in a concentration-dependent manner. Either removal of the endothelium or incubation with nitric oxide (NO) synthase inhibitor N-G-nitro-L-arginine methyl ester (L-NAME, 3 x 10(-5) M) significantly attenuated the relaxations. Pre-treatment with L-arginine (10(-3) M), but not with D-arginine, reversed the inhibitory action Of L-NAME. Indomethacin (10(-6) M) and tetraethylammonium (TEA, 10(-2) M) did not affect the relaxant responses to omeprazole indicating the lack of involvement of cyclooxygenase products and K+ channels, respectively. These results suggest a role of NO in the mechanism of action of omeprazole.