Journal article
Role of nitrosyl factors in the hindlimb vasodilation elicited by baroreceptor afferent nerve stimulation
American journal of physiology. Regulatory, integrative and comparative physiology, Vol.290(3), pp.R741-748
03/2006
DOI: 10.1152/ajpregu.00660.2005
PMID: 16254123
Abstract
This study determined whether electrical stimulation (ES) of the baroreceptor afferent fibers in the aortic depressor nerve (ADN) produces hindlimb vasodilation in pentobarbital-anesthetized rats via the release of nitric oxide (NO)-containing (nitrosyl) factors from NO synthase-positive lumbar sympathetic nerve terminals. ES of the ADN (1-10 Hz for 15 s) produced frequency-dependent reductions in mean arterial blood pressure (MAP) and mesenteric and hindlimb vascular resistance (MR and HLR, respectively). The falls in resistance were substantially smaller in hindlimb beds in which the ipsilateral lumbar sympathetic chain had been transected 7-10 days previously. The maximal falls in MR and hindquarter vascular resistance (HQR) produced by 1- to 10-Hz ES of the ADN were unaffected by the specific inhibitor of neuronal NO synthase 7-nitroindazole (7-NI, 45 mg/kg iv). However, the total falls in HQR (mmHg.kHz(-1).s) produced by these stimuli were significantly diminished by 7-NI, whereas the total falls in MR were not affected. Four successive episodes of 10-Hz ES produced equivalent reductions in MAP, MR, and HQR. The peak changes in these parameters were not affected by 7-NI. However, the total falls in HQR progressively diminished with each successive stimulus, whereas the total falls in MR remained unchanged. These results provide evidence that the hindlimb vasodilation produced by ES of baroreceptor afferents within the ADN may involve the activation of postganglionic lumbar sympathetic vasodilator fibers, which release newly synthesized and preformed nitrosyl factors.
Details
- Title: Subtitle
- Role of nitrosyl factors in the hindlimb vasodilation elicited by baroreceptor afferent nerve stimulation
- Creators
- Olga S Possas - Department of Pharmacology, University of Iowa, 11 Seashore Hall E, Iowa City, Iowa 52242-1407, USAAlan Kim JohnsonStephen J Lewis
- Resource Type
- Journal article
- Publication Details
- American journal of physiology. Regulatory, integrative and comparative physiology, Vol.290(3), pp.R741-748
- DOI
- 10.1152/ajpregu.00660.2005
- PMID
- 16254123
- ISSN
- 0363-6119
- eISSN
- 1522-1490
- Grant note
- HL-14388 / NHLBI NIH HHS DK-66086 / NIDDK NIH HHS HL-57472 / NHLBI NIH HHS
- Language
- English
- Date published
- 03/2006
- Academic Unit
- Psychological and Brain Sciences; Neuroscience and Pharmacology; Health and Human Physiology
- Record Identifier
- 9984213422702771
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