NG-METHYL-L-ARGININE, AN INHIBITOR OF L-ARGININE-DERIVED NITRIC-OXIDE SYNTHESIS, STIMULATES RENAL SYMPATHETIC-NERVE ACTIVITY INVIVO - A ROLE FOR NITRIC-OXIDE IN THE CENTRAL REGULATION OF SYMPATHETIC TONE

被引:400
作者
SAKUMA, I
TOGASHI, H
YOSHIOKA, M
SAITO, H
YANAGIDA, M
TAMURA, M
KOBAYASHI, T
YASUDA, H
GROSS, SS
LEVI, R
机构
[1] HOKKAIDO UNIV, SCH MED, DEPT PHARMACOL, SAPPORO, HOKKAIDO 060, JAPAN
[2] HOKKAIDO UNIV, APPL ELECT RES INST, DIV BIOPHYS, SAPPORO, HOKKAIDO 060, JAPAN
[3] CORNELL UNIV, MED CTR, COLL MED, DEPT PHARMACOL, NEW YORK, NY 10021 USA
关键词
NITRIC OXIDE; NG-METHYL-L-ARGININE; CENTRAL SYMPATHETIC REGULATION; BLOOD PRESSURE REGULATION; VASOCONSTRICTORS; RENAL NERVE ACTIVITY;
D O I
10.1161/01.RES.70.3.607
中图分类号
R5 [内科学];
学科分类号
1002 ; 100201 ;
摘要
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 N(G)-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-mu-mol/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.
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页码:607 / 611
页数:5
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