Dataset Information

Dissociation between sympathetic nerve traffic and sympathetically mediated vascular tone in normotensive human obesity.

ABSTRACT: Obesity increases the risk of hypertension and its cardiovascular complications. This has been partly attributed to increased sympathetic nerve activity, as assessed by microneurography and catecholamine assays. However, increased vasoconstriction in response to obesity-induced sympathoactivation has not been unequivocally demonstrated in obese subjects without hypertension. We evaluated sympathetic alpha-adrenergic vascular tone in the forearm by brachial arterial infusion of the alpha-adrenoreceptor antagonist phentolamine (120 microg/min) in normotensive obese (daytime ambulatory arterial pressure: 123+/-1/77+/-1 mm Hg; body mass index: 35+/-1 kg/m(2)) and lean (daytime ambulatory arterial pressure: 123+/-2/77+/-2 mm Hg; body mass index: 22+/-1 kg/m(2)) subjects (n=25 per group) matched by blood pressure, age, and gender. Microneurographic sympathetic nerve activity to skeletal muscle was significantly higher in obese subjects (30+/-3 versus 22+/-1 bursts per minute; P=0.02). Surprisingly, complete alpha-adrenergic receptor blockade by phentolamine (at concentrations sufficient to completely inhibit norepinephrine and phenylephrine-induced vasoconstriction) caused equivalent vasodilatation in obese (-57+/-2%) and lean subjects (-57+/-3%; P=0.9). In conclusion, sympathetic vascular tone in the forearm circulation is not increased in obese normotensive subjects despite increased sympathetic outflow. Vasodilator factors or mechanisms occurring in obese normotensive subjects could oppose the vasoconstrictor actions of increased sympathoactivation. Our findings may help to explain why some obese subjects are protected from the development of hypertension.

SUBMITTER: Agapitov AV

PROVIDER: S-EPMC4222518 | biostudies-literature | 2008 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Dissociation between sympathetic nerve traffic and sympathetically mediated vascular tone in normotensive human obesity.

Agapitov Alexei Vasilievich AV Correia Marcelo Lima de Gusmão ML Sinkey Christine Ann CA Haynes William Geoffrey WG

Hypertension (Dallas, Tex. : 1979) 20080811 4

Obesity increases the risk of hypertension and its cardiovascular complications. This has been partly attributed to increased sympathetic nerve activity, as assessed by microneurography and catecholamine assays. However, increased vasoconstriction in response to obesity-induced sympathoactivation has not been unequivocally demonstrated in obese subjects without hypertension. We evaluated sympathetic alpha-adrenergic vascular tone in the forearm by brachial arterial infusion of the alpha-adrenore ...[more]

PMID: 18695151

Similar Datasets

Project description:Aim: We generated mice lacking Irs2 which mediates signaling pathways from insulin and IL-4 specifically in lyzM Cre expressing cells. We isolated BMDM from control and Irs2LyzM-/- mice and compared their differential gene expression under veihicle, IL-4 and LPS treatment by performing mRNA sequencing studies. Methods: BMDM from control and Irs2LyzM-/- mice were treated for 24 hours with vehicle, IL-4 (10 ng/ml) or LPS (100 ng/ml). RNA integrity was confirmed and concentration measured using a Bioanalyzer. cDNA libraries were created from up to 5 μg total RNA. There were three (Irs2LyzM-/-) and four (control) biological replicates for each group and each biological replicate was divided into eight technical replicates and sequenced on individual lanes on the Illumina HiSeq 2000 (100 bp paired-end read length) at the Sanger Institute. Raw reads from the sequenced RNAseq libraries were mapped with Tophat splice junction aligner (Kim, Pertea et al. 2013), version 2.0.8 against Ensembl mouse genome reference sequence assembly (mm9) and transcript annotations. All parameters were set to default except inner distance between mate pairs (r = 130). Gene-based read counts were then obtained using the HTSeq count module (version 0.5.4p3). Differential expression analysis was performed on the counts data using the DESeq2 Bioconductor package (version 1.16.1). The GSEA preranked tool from GSEA version 2.2.4 was used forGeneset enrichment analysis. Gene ontology enrichment analysis was also performed using the topGo Bioconductor package separately for up and down-regulated genes in the comparisons analysed ( A. Alexa, J. Rahnenfuhrer, topGO: Enrichment Analysis for Gene Ontology. R package version 2.24.0 (2016)). Results: The mRNA seq. results reveal an anti- inflammatory transcriptional profile in LPS-treated Irs2LyzM-/- BMDM compared to control BMDM. Deletion of Irs2 in BMDM under all conditions (vehicle, IL-4 and LPS) manifest alteratons in genes involved in scavenging catecholamines and supporting increased sympathetic innervation.

Dataset Information

Dissociation between sympathetic nerve traffic and sympathetically mediated vascular tone in normotensive human obesity.

Publications

Dissociation between sympathetic nerve traffic and sympathetically mediated vascular tone in normotensive human obesity.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets