Intrarenal RAS activity and urinary angiotensinogen excretion in anti-thymocyte serum nephritis rats.

Abstract

The differential roles of circulating and intrarenal renin-angiotensin system (RAS) in glomerulonephritis have not been elucidated. In this study, we investigated the levels of circulating and intrarenal RAS activity and urinary angiotensinogen (AGT) excretion in anti-thymocyte serum (ATS) nephritis induced by an ATS injection (ATS group). The effect of olmesartan, an angiotensin II (ANG II) type 1 receptor blocker (ARB), on the development of nephritis was also examined (ATS+ARB group). In addition, the rats received a saline injection instead of ATS (control group). Mesangial proliferation with transient proteinuria, which peaked at day 7, was significantly increased in the ATS group compared with the control group. The levels of glomerular AGT mRNA, intrarenal ANG II, and urinary AGT excretion in the ATS group were increased significantly at day 7 compared with the control group. Administration of olmesartan (ATS+ARB group) significantly decreased the levels of renal lesions, proteinuria, and intrarenal RAS activity compared with the ATS group. In addition, the levels of urinary AGT excretion correlated with the levels of glomerular damage, urinary protein excretion, and immunoreactivity for AGT and ANG II in kidney. On the other hand, plasma renin activity was significantly lower in the ATS group compared with the control group and significantly higher in the ATS+ARB group than in the ATS group. These data suggest that an increase in kidney-specific RAS activity, which parallels urinary AGT excretion, plays an important role in the development of ATS nephritis.

• Authors: Naro Ohashi, Tatsuo Yamamoto, Yanjie Huang, Taro Misaki, Hirotaka Fukasawa, Hiroyuki Suzuki, Akashi Togawa, Sayuri Suzuki, Yoshihide Fujigaki, Tsutomu Nakagawa, Yukio Nakamura, Fumiaki Suzuki, Masatoshi Kitagawa, Akira Hishida
• Journal: American journal of physiology. Renal physiology (Am J Physiol Renal Physiol) Vol. 295 Issue 5 Pg. F1512-8 (Nov 2008) ISSN: 1931-857X [Print] United States
• PMID: 18784264 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Angiotensin II Type 1 Receptor Blockers
• Antilymphocyte Serum
• Imidazoles
• RNA, Messenger
• Tetrazoles
• Angiotensinogen
• Angiotensin II
• olmesartan
• Renin

Topics

• Angiotensin II (blood, metabolism)
• Angiotensin II Type 1 Receptor Blockers (pharmacology)
• Angiotensinogen (genetics, metabolism, urine)
• Animals
• Antilymphocyte Serum (pharmacology)
• Blood Pressure (physiology)
• Gene Expression (drug effects)
• Glomerulonephritis, Membranoproliferative (pathology, physiopathology, urine)
• Imidazoles (pharmacology)
• Kidney (drug effects, metabolism, pathology)
• Male
• Proteinuria (urine)
• RNA, Messenger (genetics, metabolism)
• Rats
• Rats, Wistar
• Renin (blood)
• Renin-Angiotensin System (physiology)
• Tetrazoles (pharmacology)