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NG-methyl-L-arginine, an inhibitor of L-arginine-derived nitric oxide synthesis, stimulates renal sympathetic nerve activity in vivo. A role for nitric oxide in the central regulation of sympathetic tone?
- Source :
-
Circulation research [Circ Res] 1992 Mar; Vol. 70 (3), pp. 607-11. - Publication Year :
- 1992
-
Abstract
- Continuous production of endothelium-derived nitric oxide (NO) in peripheral vessels has been shown to modulate vascular resistance and blood pressure. NO is also formed in the brain upon activation of glutamate receptors, which are thought to mediate central autonomic reflexes. In the present study we assessed whether NO plays a role in central autonomic regulation. For this, we have investigated the effects of NG-methyl-L-arginine (NMA), a selective inhibitor of NO synthesis from L-arginine, on sympathetic renal nerve activity (RNA), blood pressure, and heart rate in the anesthetized rat. NMA elicited a dose-dependent sustained increase in blood pressure (approximately 20 and 30 mm Hg, 5 minutes after 10 and 50 mumol/kg i.v., respectively). Heart rate and RNA decreased transiently (15 beats per minute and 40%, respectively); RNA subsequently increased (100%) while blood pressure remained elevated. Baroreceptor deafferentation markedly altered these responses to NMA; the transient decreases in heart rate and RNA were abolished, whereas the increases in RNA and blood pressure were significantly potentiated. After spinal C-1-C-2 transection, there was no increase in RNA, and blood pressure increased to a smaller extent. L-Arginine blocked the NMA-induced increases in blood pressure and RNA. Thus, in addition to modulating vascular resistance by a peripheral action, NO may also play a role in the central regulation of sympathetic tone.
- Subjects :
- Animals
Arginine pharmacology
Blood Pressure drug effects
Heart Rate drug effects
Homeostasis
Male
Neural Conduction
Neural Inhibition
Rats
Rats, Inbred Strains
Vagotomy
omega-N-Methylarginine
Arginine analogs & derivatives
Arginine antagonists & inhibitors
Kidney innervation
Nitric Oxide metabolism
Sympathetic Nervous System drug effects
Subjects
Details
- Language :
- English
- ISSN :
- 0009-7330
- Volume :
- 70
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- Circulation research
- Publication Type :
- Academic Journal
- Accession number :
- 1537096
- Full Text :
- https://doi.org/10.1161/01.res.70.3.607