RGD Reference Report - Activation of ETB receptors increases superoxide levels in sympathetic ganglia in vivo. - Rat Genome Database

Send us a Message



Submit Data |  Help |  Video Tutorials |  News |  Publications |  Download |  REST API |  Citing RGD |  Contact   

Activation of ETB receptors increases superoxide levels in sympathetic ganglia in vivo.

Authors: Lau, YE  Galligan, JJ  Kreulen, DL  Fink, GD 
Citation: Lau YE, etal., Am J Physiol Regul Integr Comp Physiol. 2006 Jan;290(1):R90-5. Epub 2005 Sep 22.
RGD ID: 1581856
Pubmed: PMID:16179487   (View Abstract at PubMed)
DOI: DOI:10.1152/ajpregu.00505.2005   (Journal Full-text)

Dai and colleagues (Dai X, Galligan JJ, Watts SW, Fink GD, and Kreulen DL. Hypertension 43: 1048-1054, 2004) found that endothelin (ET) stimulated O2- production in sympathetic ganglion neurons in vitro by activating ET(B) receptors. The objective of the present study was to determine whether activation of ET(B) receptors in vivo elevates O2- levels in sympathetic ganglia. Because ET(B) receptor activation increases blood pressure, we also sought to determine whether alteration in O2- levels was a direct effect of ET(B) receptor activation on sympathetic ganglia or an indirect consequence of hypertension. Male Sprague-Dawley rats received intravenous infusions of either the specific ET(B) receptor agonist sarafotoxin 6c (S6c; 5 pmol.kg(-1).min(-1)) or isotonic saline at 0.01 ml/min (control) for 120 min. To measure O2- levels, we removed the inferior mesenteric ganglion immediately after infusion and stained it with dihydroethidine (DHE). Mean arterial pressure increased 26.6 +/- 1.7 mmHg in the S6c-treated rats and 3.65 +/- 6 mmHg in control rats. Measurements of average pixel intensity revealed that the DHE fluorescence in ganglionic neurons and surrounding glial cells were 96.7% and 160% greater in S6c-treated than in control rats, respectively. To evaluate the effect of elevated blood pressure on O2- production, a separate group of rats received phenylephrine (PE; 10 mug.kg(-1).min(-1) iv) for 2 h. MAP increased 31 +/- 1.2 mmHg in PE-infused rats. The DHE fluorescence intensity in ganglia of PE-infused rats was significantly greater than that of control rats, 137.7% in neurons and 104.6% in glia but significantly lower than in ganglia from S6c rats. We conclude that ET(B) receptor activation in vivo significantly enhances O2- levels in sympathetic ganglia, due to both pressor effects and direct stimulation of ET(B) receptors in ganglion cells.

Phenotype Annotations    Click to see Annotation Detail View

Mammalian Phenotype

TermQualifierEvidenceWithReferenceNotesSourceOriginal Reference(s)
increased systemic arterial blood pressure  IDA 1581856 RGD 
Objects Annotated

Genes (Rattus norvegicus)
Ednrb  (endothelin receptor type B)


Additional Information