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Regulation of renin secretion and arterial pressure during prolonged baroreflex activation: influence of salt intake.
- Source :
-
Hypertension (Dallas, Tex. : 1979) [Hypertension] 2014 Sep; Vol. 64 (3), pp. 604-9. Date of Electronic Publication: 2014 Jun 16. - Publication Year :
- 2014
-
Abstract
- Chronic electric activation of the carotid baroreflex produces sustained reductions in sympathetic activity and arterial pressure and is currently being evaluated as antihypertensive therapy for patients with resistant hypertension. However, the influence of variations in salt intake on blood pressure lowering during baroreflex activation (BA) has not yet been determined. As the sensitivity of arterial pressure to salt intake is linked to the responsiveness of renin secretion, we determined steady-state levels of arterial pressure and neurohormonal responses in 6 dogs on low, normal, and high salt intakes (5, 40, 450 mmol/d, respectively) under control conditions and during a 7-day constant level of BA. Under control conditions, there was no difference in mean arterial pressure at low (92±1) and normal (92±2 mm Hg) sodium intakes, but pressure increased 9±2 mm Hg during high salt. Plasma renin activity (2.01±0.23, 0.93±0.20, 0.01±0.01 ng angiotensin I/mL/h) and plasma aldosterone (10.3±1.9, 3.5±0.5, 1.7±0.1 ng/dL) were inversely related to salt intake, whereas there were no changes in plasma norepinephrine. Although mean arterial pressure (19-22 mm Hg) and norepinephrine (20%-40%) were lower at all salt intakes during BA, neither the changes in pressure nor the absolute values for plasma renin activity or aldosterone in response to salt were different from control conditions. These findings demonstrate that suppression of sympathetic activity by BA lowers arterial pressure without increasing renin release and indicate that changes in sympathetic activity are not primary mediators of the effect of salt on renin secretion. Consequently, blood pressure lowering during BA is independent of salt intake.<br /> (© 2014 American Heart Association, Inc.)
- Subjects :
- Aldosterone blood
Animals
Blood Pressure drug effects
Dogs
Dose-Response Relationship, Drug
Heart Rate drug effects
Heart Rate physiology
Hematocrit
Models, Animal
Neurotransmitter Agents metabolism
Renin metabolism
Baroreflex physiology
Blood Pressure physiology
Renin blood
Sodium Chloride, Dietary pharmacology
Subjects
Details
- Language :
- English
- ISSN :
- 1524-4563
- Volume :
- 64
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- Hypertension (Dallas, Tex. : 1979)
- Publication Type :
- Academic Journal
- Accession number :
- 24935941
- Full Text :
- https://doi.org/10.1161/HYPERTENSIONAHA.114.03788