Systemic administration of lipopolysaccharide upregulates angiotensin II expression in rat renal tubules: Immunohistochemical and ELISA studies

We investigated whether angiotensin II (AII) peptide is induced in the rat kidney under endotoxemic conditions. Immunohistochemistry revealed strong All-like immunoreactivity in the renal tubules of rats given high-dose lipopolysaccharide (LPS; 1000 mu g/kg) intraperitoneally (i.p.). All-like immunoreactivity in renal tubules was slight at I h after the LPS injection, but marked at 3 h. There were few signals in the kidney in saline-injected control rats. When injected at 0.1, 10, or 1000 mu g/kg i.p., LPS-induced a dose-related increase in All-like immunoreactivity in renal tubules that was unaffected by treatment with the prostaglandin-synthesis blocker indomethacin. ELISA measurement of the All concentration in the whole kidney supported the above findings. These results suggest that systemically administered LPS induces All peptide expression in renal tubules by a prostaglandin-independent mechanism. (c) 2005 Elsevier Inc. All rights reserved.