Chemerin influences endothelin- and serotonin-induced pulmonary artery vasoconstriction in rats

Chemerin has been recently identified as a vasoactive adipokine implicated in blood pressure regulation. In this context, we evaluated whether chemerin could influence pulmonary vasoreactive response.

Vascular reactivity to chemerin and to phenylephrine, serotonin and endothelin-1 after chemerin pretreatment was evaluated in rat isolated pulmonary artery versus thoracic aorta with and without endothelium. Vasoreactivity to acetylcholine in presence of nitric oxide (NO)-synthase inhibitor (L-NAME) and to NO donor sodium nitroprusside (SNP) was evaluated in chemerin-pretreated pulmonary artery versus thoracic aorta with endothelium. Pretreatment with ODQ, a soluble guanylate cyclase inhibitor and apocynin, a ROS production inhibitor, were also tested. Arteries and lung tissue were harvested for pathobiological evaluation.

Chemerin contracted endothelium-denuded pulmonary artery, while no response was observed in arteries with endothelium. Chemerin potentiated phenylephrine-, endothelin-1- and serotonin-induced vasoconstriction, which was further enhanced by endothelium removal. Chemerin decreased acetylcholine-induced vasorelaxation in arteries with endothelium, while it did not affect SNP-induced relaxation. In presence of L-NAME, there remained a vasorelaxation in chemerin-pretreated arteries. Chemerin or ODQ alone partly decreased acetylcholine-induced vasorelaxation in pulmonary artery and thoracic aorta, while combined chemerin and ODQ incubation abolished it. Treatment with apocynin partly or totally reversed chemerin effects. In both types of arteries, chemerin reduced acetylcholine-induced NO production, as well as endothelial and inducible NO-synthase expression.

Chemerin potentiates vascular responses to vasoconstrictors in pulmonary artery and thoracic aorta and, impairs acetylcholine-induced pulmonary artery vasodilatation, by mechanisms involving at least partly NO signaling and oxidative stress.