Sodium Intake Influences Hemodynamic and Neural Responses to Angiotensin Receptor Blockade in Rostral Ventrolateral Medulla
| Autor: | S Y Jones, Gerald F. DiBona |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Male
medicine.medical_specialty Mean arterial pressure Angiotensin receptor Sympathetic Nervous System Microinjections food.diet Tetrazoles Angiotensin-Converting Enzyme Inhibitors Blood Pressure Low sodium diet Kidney Losartan Rats Sprague-Dawley Renin-Angiotensin System Angiotensin Receptor Antagonists food Heart Rate Internal medicine Renin Renin–angiotensin system Internal Medicine medicine Animals Antihypertensive Agents Heart Failure Medulla Oblongata Receptors Angiotensin Dose-Response Relationship Drug business.industry Biphenyl Compounds Hemodynamics Sodium Dietary Rostral ventrolateral medulla Baroreflex Angiotensin II Peptide Fragments Rats Candesartan Endocrinology Blood pressure Benzimidazoles Angiotensin I business medicine.drug |
| Zdroj: | Hypertension. 37:1114-1123 |
| ISSN: | 1524-4563 0194-911X |
| DOI: | 10.1161/01.hyp.37.4.1114 |
| Popis: | Abstract —To determine the effects of physiological alterations in endogenous angiotensin II activity on basal renal sympathetic nerve activity (RSNA) and its arterial baroreflex regulation, angiotensin II type 1 receptor antagonists were microinjected into the rostral ventrolateral medulla of anesthetized rats consuming a low, normal, or high sodium diet that were instrumented for simultaneous measurement of arterial pressure and RSNA. Plasma renin activity was increased in rats fed a low sodium diet and decreased in those fed a high sodium diet. Losartan (50, 100, and 200 pmol) decreased heart rate and RSNA (but not mean arterial pressure) dose-dependently; the responses were significantly greater in rats fed a low sodium diet than in those fed a high sodium diet. Candesartan (1, 2, and 10 pmol) decreased mean arterial pressure, heart rate, and RSNA dose-dependently; the responses were significantly greater in rats fed a low sodium diet than in those fed a normal or high sodium diet. [D-Ala 7 ]Angiotensin-(1-7) (100, 200, and 1000 pmol) did not affect mean arterial pressure, heart rate, or RSNA in rats fed either a low or a high sodium diet. In rats fed a low sodium diet, candesartan reset the arterial baroreflex control of RSNA to a lower level of arterial pressure, and in rats with congestive heart failure, candesartan increased the arterial baroreflex gain of RSNA. Physiological alterations in the endogenous activity of the renin-angiotensin system influence the bradycardic, vasodepressor, and renal sympathoinhibitory responses to rostral ventrolateral medulla injection of antagonists to angiotensin II type 1 receptors but not to angiotensin-(1-7) receptors. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|