The role of nitric oxide in two-kidney, one-clip renovascular hypertensive rats
Yokokoji, K.; Otsuka, Y.; Okabe, T.; Kanmatsuse, K.
Nihon Jinzo Gakkai Shi 39(4): 395-399
1997
ISSN/ISBN: 0385-2385 PMID: 9198361 Document Number: 474072
The relationship between blood pressure(BP) and nitric oxide(NO) in two-kidney, one-clip renovascular hypertensive rats (2K1C) was investigated. Although urinary NO2- + NO3-(NOx) excretion (UNOX V) increased 2 weeks after surgery (2W-2K1C), UNOX V decreased 4 weeks after surgery (4W-2K1C) compared with that of the control. UNOX V levels were restored 2 weeks after unclipping (U2K1C). BP and UNOX V did not change in 2K1C after treatment with L-arginine (Arg-2K1C). Aorta from 4W-2K1C and Arg-2K1C showed significantly decreased relaxation responses to acetylcholine(Ach), but Ach-induced relaxation of aorta in U2K1C returned to control-level responses. De-endothelialized aorta from 4W-2K1C, Arg-2K1C, and U2K1C had significantly decreased relaxation responses to lipopolysaccharide. These data suggest that: (1) transient increase of NO synthesis is accompanied by elevation of BP, but long-term elevation of BP decreases NO synthesis in endothelium and smooth muscle cells: (2) L-arginine supplement has no effect on the development of hypertension and on NO production by endothelium and smooth muscle cells in 2K1C.