Fig. 1.

Chemerin (Chem) decreases insulin-induced vasodilatation via chemerin receptor 23 (ChemR23)-, Akt/nitric oxide (NO)-, and oxidative stress-dependent mechanisms. Endothelium-intact mesenteric arteries from C57BL/6J mice were incubated with chemerin (0.5 ng/ml) or vehicle for 1 h. Relaxation response to insulin was evaluated in the absence (A) and presence (B) of CCX832 (CCX; ChemR23 antagonist), YS-49 [phosphatidylinositol 3-kinase activator (PI3K); C] or Tiron (ROS scavenger; D), which were added 30 min before vehicle or chemerin. Vehicle and chemerin curves in A–D were originated from the same sets of experiments. E: phosphorylation of endothelial NO synthase (eNOS; Ser¹¹⁷⁷) was determined by Western blot analysis in endothelial cells stimulated with chemerin (0.5 ng/ml, 1 h) and insulin (30 min) in the absence or presence of CCX832, N-acetyl-cysteine (NAC; ROS scavenger), or 740Y-P (PI3K activator). peNOS, phosphorylated eNOS; teNOS, total eNOS. Values were normalized by total NOS expression. F: NO production was determined by diacetate 4-amino-5-methylamino-2′,7′-difluorofluorescein diacetate fluorescence in endothelial cells, and values were normalized by the protein amount. Results are means ± SE of 5−6 experiments. Data were analyzed using one-way ANOVA followed by a post hoc Tukey test. *P < 0.05 vs. vehicle; #P < 0.05 vs. chemerin; ^σP < 0.05 vs. insulin; ^φP < 0.05 vs. chemerin + insulin.