Gr-1 cells are the major iNOS-expressing cells that suppress lymphatic contraction during the OX-induced edema. (A) iNOS-expressing cells surround the lymphatic vessel, which is highlighted with FITC-Lectin (green, LV). iNOS is stained with FITC-labeled antibody (green, punctuate stain). Upper, F4/80; Lower, Gr-1 (red). (B) Gr-1 antibody treatment maintains stronger lymphatic contraction compared with Rat IgG control antibody treatment. , Control IgG, n = 8; , Gr-1 antibody, n = 9. *P < 0.05.