The role of arachidonic acid/cyclooxygenase cascade,phosphodiesterase IV and Rho-kinase in H2S-induced relaxation in the mouse corpus cavernosum

Background penile corpus cavernosum is an extremely vascularized tissue and cavernosal smooth muscle tone is regulated by the balance between contractile and relaxant factor. we investigated the possible role of arachidonic acid/cyclooxygenase cascade,phosphodiesterase iv (pdeiv) and rho-kinase in exogenous hydrogen sulfide (h2s)-induced relaxation in mouse corpus cavernosum. methods the relaxant response to h2s (nahs as exogenous h2s; 1–1000 μm) were obtained in isolated mouse corpus cavernosum tissues which pre-contracted by phenylephrine (5 μm). the effects of 4-(4-octadecylphenyl)-4-oxobutenoic acid (obaa; 10 μm),a selective phospholipase a2 (pla2) inhibitor,indomethacin (1 μm),a non-selective cyclooxygenase (cox) inhibitor,baicalein (10 μm),a lipoxygenase (lox) inhibitor,and proadifen (10 μm),cytochrome p450 inhibitor,on the relaxant responses to h2s were investigated. furthermore,the effects of theophylline (500 μm) and rolipram (1 μm),a non-selective and selective pdeiv inhibitor,and fasudil (3 μm),a specific rho-kinase inhibitor,were studied on h2s-induced relaxation. results h2s-induced relaxations were significantly reduced by obaa,indomethacin and proadifen but not baicalein. furthermore,theophylline,rolipram and fasudil reduced h2s-induced relaxations. conclusion these results suggest that pla2,cox,cytochrome p450,pdeiv and rho-kinase pathway may involve in h2s-induced relaxation in mouse corpus cavernosum tissues. © 2017 institute of pharmacology,polish academy of sciences