ANG II receptor blockade and arterial baroreflex regulation of renal nerve activity in cardiac failure
| Autor: | S. Y. Jones, Virginia L. Brooks, Gerald F. DiBona |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
Male
Nitroprusside medicine.medical_specialty Sympathetic nervous system Sympathetic Nervous System Physiology Tetrazoles Kidney Losartan Methoxamine Rats Sprague-Dawley Angiotensin Receptor Antagonists Physiology (medical) Internal medicine Renin–angiotensin system medicine Animals Injections Intraventricular Heart Failure business.industry Biphenyl Compounds Imidazoles Arteries Baroreflex medicine.disease Angiotensin II Rats Endocrinology Blood pressure medicine.anatomical_structure Heart failure Injections Intravenous cardiovascular system business circulatory and respiratory physiology medicine.drug |
| Zdroj: | American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. 269:R1189-R1196 |
| ISSN: | 1522-1490 0363-6119 |
| DOI: | 10.1152/ajpregu.1995.269.5.r1189 |
| Popis: | In cardiac failure, efferent renal sympathetic nerve activity (ERSNA) and the activity of the renin-angiotensin system are increased, and arterial baroreflex regulation of ERSNA is attenuated. We examined the effect of intravenous and intracerebroventricular angiotensin II AT receptor blockade with losartan on the arterial baroreflex regulation of ERSNA in conscious control (C) and congestive heart failure (CHF) rats. Intravenous losartan (10 mg/kg, 21.7 mumol/kg) decreased arterial pressure more in CHF than in C rats (-28 +/- 3 vs. -20 +/- 3 mmHg, P < 0.05). After restoration of arterial pressure to the prelosartan value with methoxamine infusion, ERSNA was decreased more in CHF than in C rats (-23 +/- 4 vs. -1 +/- 2%, P < 0.05). Maximal gain of arterial baroreflex control of ERSNA (Gmax) was lower in CHF compared with C rats (-1.94 +/- 0.10 vs. -3.78 +/- 0.21%/mmHg, P < 0.05). Intravenous losartan increased Gmax in CHF (to -3.01 +/- 0.14%/mmHg, P < 0.05) but not in C rats (to -3.56 +/- 0.19%/mmHg). Intracerebroventricular losartan (4.61 micrograms, 10 nmol) did not affect arterial pressure but decreased ERSNA more in CHF than in C rats (-13 +/- 2 vs. -8 +/- 3%, P < 0.05). Like intravenous losartan, intracerebroventricular losartan increased Gmax in CHF (from -2.11 +/- 0.18 to -3.21 +/- 0.30%/mmHg, P < 0.05) but not in C rats (from -3.98 +/- 0.25 to -3.84 +/- 0.22%/mmHg). These results suggest that increased activity of the renin-angiotensin system contributes to the increase in ERSNA and its abnormal arterial baroreflex regulation in cardiac failure. |
| Databáze: | OpenAIRE |
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