Involvement of pressure-related mechanism in activation of inducible nitric oxide synthase.
The goal of this study was to clarify the relationship between blood pressure and inducible nitric oxide synthase (iNOS) activity. Different levels of blood pressure were obtained by long-term (six days) intravenous infusion of different concentrations (0.3%-8%) of NaCl solution to normal SD rats. iNOS activity assay and measurement of urinary nitrate/nitrite (UNOx), an index of NO production of the whole body, were carried out by isotope-labeled L-arginine conversion rate measurement and Greiss Reaction respectively. Groups of normotensive and hypertensive rats including normal Wistar rats, normal Sprague-Dawley (SD) rats, high NaCl-induced hypertensive rats (NaHR) and spontaneously hypertensive rats (SHR) were used to detect the changes in iNOS protein under normotension and hypertension by Western blotting. iNOS activity of aorta and kidney tissues and UNOx increased more significantly in hypertensive animals than in the normotensive control ones. Accordingly, iNOS protein in the aortas of NaHR and SHR increased by 149% and 261% respectively. It is suggested that in addition to cytokine and bacterial products etc, blood pressure is also an effective regulatory factor involved in iNOS activation and expression.
Tan
D Y
DY
Department of Pathophysology, Jinan University Medical College, Guangzhou 510632. tdytan@jnu.edu.cn
Cheng
S B
SB
Chen
X L
XL
Zhang
S M
SM
Yang
H Z
HZ
Peng
X
X
Tang
C S
CS
Zhang
C
C
Meng
X Z
XZ
D000818:Animals; D001794:Blood Pressure / Q000502:physiology*; D006973:Hypertension / Q000139:chemically induced / Q000378:metabolism; D008297:Male; D009569:Nitric Oxide / Q000096:biosynthesis; D019001:Nitric Oxide Synthase / Q000096:biosynthesis / Q000378:metabolism*; D051381:Rats; D011918:Rats, Inbred SHR; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D012965:Sodium Chloride / Q000494:pharmacology
D009569:Nitric Oxide; D012965:Sodium Chloride; D019001:Nitric Oxide Synthase