The role of subtypes of voltage-gated K⁺ channels in pulmonary vasoconstriction induced by 15-hydroeicosatetraenoic acid

AimTo observe the effect of subtypes of Kv channels in rat pulmonary artery smooth muscle cells (PASMCs) on the process of pulmonary vasoconstriction induced by 15-HETE. MethodsIn the present study, ring of rabbit PA with specific K_V channel blockers were employed to functionally identify certain channel subtypes that took part in the process of 15-HETE induced pulmonary vasoconstriction; RT-PCR and Western blotting analysis were also used to measure the expression of subtypes of K_V in PASMCs exposed to 15-HETE，chronic hypoxia. ResultsBlocking of Kv1.1, Kv1.2, Kv1.3 and Kv1.6 channels did not affect 15-HETE induced vasoconstriction in normoxic rats; 15-HETE did not affect expression of Kv1.1 and Kv1.2 channels; 15-HETE significantly downregulated the expression of mRNA and protein of Kv1.5 and Kv2.1 in rat PASMCs. ConclusionThe results suggested that hypoxia may block Kv1.5 and Kv2.1 channels via 15-HETE mediated mechanism, leading to decrease numbers of functional Kv1.5 and Kv2.1 channels in PASMCs, leading to PA vasoconstriction.