Facilitatory role of NO in neural norepinephrine release in the rat kidney

Hideki Tanioka, Koichi Nakamura, Shinsei Fujimura, Makoto Yoshida, Mizue Suzuki-Kusaba, Hiroaki Hisa, Susumu Satoh

Research output: Contribution to journalArticlepeer-review

20 Citations (Scopus)

Abstract

We examined modulation by nitric oxide (NO) of sympathetic neurotransmitter release and vasoconstriction in the isolated pump-perfused rat kidney. Electrical renal nerve stimulation (RNS; 1 and 2 Hz) increased renal perfusion pressure and renal norepinephrine (NE) efflux. Nonselective NO synthase (NOS) inhibitors [Nω-nitro-L-arginine methyl ester (L-NAME) or Nω-nitro-L-arginine], but not a selective neuronal NO synthase inhibitor (7-nitroindazole sodium salt), suppressed the NE efflux response and enhanced the perfusion pressure response. Pretreatment with L-arginine prevented the effects of L-NAME on the RNS-induced responses. 2-(4-Carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (carboxy-PTIO), which eliminates NO by oxidizing it to NO2, suppressed the NE efflux response, whereas the perfusion pressure response was less susceptible to carboxy-PTIO. 8-Bromoguanosine cGMP suppressed and a guanylate cyclase inhibitor [4H-8-bromo-1,2,4-oxadiazolo(3,4-d)benz(b)(1,4)oxazin-1-one] enhanced the RNS-induced perfusion pressure response, but neither of these drugs affected the NE efflux response. These results suggest that endogenous NO facilitates the NE release through cGMP-independent mechanisms, NO metabolites formed after NO2 rather than NO itself counteract the vasoconstriction, and neuronal NOS does not contribute to these modulatory mechanisms in the sympathetic nervous system of the rat kidney.

Original languageEnglish
Pages (from-to)R1436-R1442
JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
Volume282
Issue number5 51-5
DOIs
Publication statusPublished - 2002

Keywords

  • Guanylate cyclase inhibitor
  • Nitric oxide scavenger
  • Nitric oxide synthase inhibitor
  • Sympathetic nerves
  • Vasoconstriction

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

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