Effect of Ang II-induced leukocyte responses within rat mesenteric arterioles. Rats were treated intraperitoneally with saline (n = 6), 0.1 nM Ang II (n = 5), or 1 nM Ang II (n = 6). Four hours later arteriolar leukocyte adhesion was quantified. A group of animals was pretreated with losartan (n = 5) 15 minutes before intraperitoneal injections of 1 nM Ang II, and responses were evaluated 4 hours later. A final group was intraperitoneally treated with 1 nM Ang II, and 24 hours later arteriolar leukocyte adhesion was determined. Results are represented as mean ± SEM. ^*P < .05 and ^**P < .01 relative to the saline group. ++P < .01 relative to the 1 nM Ang II group.