Oxidative stress in the Dahl salt-sensitive hypertensive rat.
Oxidative stress has been proposed as important in the pathogenesis of hypertension. Measurement of 8-iso prostaglandin F2alpha (8-ISO) is introduced for evaluating oxidative stress in vivo. 8-ISO is the major urinary metabolite of F2-isoprostanes and is formed nonenzymatically from the attack of superoxide radicals on arachidonic acid. We examined the oxidative stress level in the Dahl salt-sensitive (Dahl-S) rats and the Dahl salt-resistant (Dahl-R) rats. Dahl-S and Dahl-R rats were fed either a high salt diet (8% NaCl; HS) or low salt diet (0.3% NaCl; LS) for 3 weeks, and systolic blood pressure (SBP) and 24-hr urinary excretion of 8-ISO (U-8-ISO) were measured. In Dahl-S rats, the high salt diet induced hypertension (139 +/- 3 mmHg in LS versus 186 +/- 2 mmHg in HS, p < .05) and significantly increased the U-8-ISO (24.9 +/- 3.6 ng/24 hr in LS versus 63.2 +/- 14.6 ng/24 hr in HS, p < .05). No significant difference in blood pressure or U-8-ISO was observed between high-salt and low-salt treated Dahl-R rats. U-8-ISO concentration was correlated with SBP in all four experimental groups (r = 0.866). Moreover, urinary 8-hydroxy-2'-deoxyguanosine (U-8-OHdG), which is one of the most commonly used markers for evaluation of oxidative stress, was higher in Dahl-S-8% rats than in Dahl-S-0.3% rats (136.1 +/- 48.4 ng/24 hr in LS versus 322.8 +/- 46.7 ng/24 hr in HS, p < .05), and U-8-OHdG was correlated with SBP (r = 0.681) in Dahl-S rats. These results suggest oxygen radicals are involved in the pathogenesis of hypertension.
Kushiro
Toshio
T
Department of Cardiology, Nihon University Surugadai Hospital, Tokyo, Japan. kushiro@med.nihon-u.ac.jp
Fujita
Hirotaka
H
Hisaki
Ryohei
R
Asai
Takae
T
Ichiyama
Izumi
I
Kitahara
Yasuyuki
Y
Koike
Miyuki
M
Sugiura
Hitoshi
H
Saito
Fumio
F
Otsuka
Yuji
Y
Kanmatsuse
Katsuo
K
D000080242:8-Hydroxy-2'-Deoxyguanosine; D000818:Animals; D015415:Biomarkers; D001794:Blood Pressure; D001835:Body Weight; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000652:urine; D015237:Dinoprost / Q000031:analogs & derivatives* / Q000652:urine; D006339:Heart Rate; D006973:Hypertension / Q000378:metabolism*; D008297:Male; D018384:Oxidative Stress / Q000502:physiology*; D051381:Rats; D020303:Rats, Inbred Dahl
D015415:Biomarkers; C075750:8-epi-prostaglandin F2alpha; D000080242:8-Hydroxy-2'-Deoxyguanosine; D015237:Dinoprost; D003849:Deoxyguanosine