February 4, 1997Circulation
Role of Superoxide in Angiotensin II–Induced but Not Catecholamine-Induced Hypertension
Why the study?
Does liposome-encapsulated SOD reduce blood pressure in rats with angiotensin II-induced hypertension compared to norepinephrine-induced hypertension?
Population
Rats with hypertension induced by a 5-day infusion of angiotensin II or norepinephrine
Comparison
Liposome-encapsulated superoxide dismutase (SOD) vs Empty liposomes
Design
Preclinical
Follow-up
5 days
Authors
Discussion
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Member takes
Implication
Supports superoxide mediation in Ang II hypertension in rats; leaves open whether targeted antioxidants benefit human high-renin states.
Key Points
- The study aims to investigate the role of superoxide in hypertension induced by angiotensin II compared to norepinephrine.
- Rats were infused with angiotensin II or norepinephrine over 5 days to induce hypertension.
- Blood pressure was measured, and treatment with liposome-encapsulated superoxide dismutase (SOD) was administered.
- Vascular superoxide production was assessed using lucigenin chemiluminescence.
- Norepinephrine infusion increased blood pressure to 179 +/- 5 mm Hg, while angiotensin II increased it to 189 +/- 4 mm Hg.
- Liposome-encapsulated SOD reduced blood pressure by 50 mm Hg in angiotensin II-infused rats, but had no effect in norepinephrine-infused rats.
- SOD treatment enhanced hypotensive responses to acetylcholine and vasodilators in angiotensin II-treated rats.
Structured PICO
Does liposome-encapsulated SOD reduce blood pressure in rats with angiotensin II-induced hypertension compared to norepinephrine-induced hypertension?
P
Population
Rats with hypertension induced by a 5-day infusion of angiotensin II or norepinephrine
I
Intervention
Liposome-encapsulated superoxide dismutase (SOD)
C
Comparator
Empty liposomes
O
Outcome
Arterial pressure and vascular superoxide (.O2-) productionsurrogate
Superoxide mediates hypertension caused by chronically elevated angiotensin II, but not norepinephrine, suggesting a specific role for oxidative stress in high renin/angiotensin II states.
Cite This Study
Laursen et al. (1997) studied this question.