Representative photomicrographs showing immunolocalization of TNFα and IL-4 in rat mesenteric arterioles and postcapillary venules. Mesentery was fixed for staining with anti-TNFα (A,C,E,G) or IL-4 (B,D,F,H) antibodies 4 hours after the intraperitoneal injection of PBS (A-D) or Ang-II (1 nM; E-H). Brown reaction product indicates positive immunoperoxidase localization on the vascular endothelium. All panels are lightly counterstained with hematoxylin. Results are representative of 4 to 5 experiments with each treatment. A 100 × 1.25 oil objective lens was used. Leica IM 1000 software capture imaging (Leica Microsystems, Wetzlar, Germany) was used to obtain the images.