Abstract
Abstract 036: Pomc Neurons, But Not Agrp Neurons, Are Required For Leptin-induced Sympathetic Activation
Hypertension (Dallas, Tex. 1979), Vol.64(Suppl_1), pp.A036-A036
11/2014
DOI: 10.1161/hyp.64.suppl_1.036
Abstract
Leptin acts in the brain to decrease food intake and promote energy expenditure by increasing sympathetic nerve activity (SNA) to thermogenic brown adipose tissue. Leptin also increases SNA to other beds including kidney with implications for obesity-induced hypertension. We previously demonstrated the importance the arcuate nucleus (Arc) of the hypothalamus in mediating leptin-induced increases in regional SNA, but the specific neuronal population within the Arc that mediates these responses is unknown. We hypothesized that agouti-related peptide (AgRP) and/or proopiomelanocortin (POMC) neurons of the Arc are critical for the increases in SNA in response to leptin. To test this, we generated mice lacking the leptin receptor specifically in AgRP or POMC neurons by crossing the LepRmice with AgRP or POMC mice. Consistent with previous reports, both AgRPLepR mice and POMC/LepR mice have a slightly elevated body weight relative to littermate controls. Next, we used multifiber sympathetic nerve recording to assess the SNA effects of leptin. Intracerebroventricular (ICV) injection of leptin (2 μg) led to a comparable increase in renal SNA in control mice (210±93%) and AgRP/LepR mice (191±53%). AgRPLepR mice also displayed a normal lumbar SNA response to ICV leptin (384±86%) relative to controls (325±46%). In contrast, POMC/LepR mice exhibited a significantly reduced renal SNA response to ICV leptin (5±17%) as compared to controls (174±45%). Lumbar SNA response to leptin was also blunted in POMC/LepR mice (24±21%) as compared to controls (358±53%). Thus, deletion of the leptin receptor from POMC neurons, but not AgRP neurons, interferes with the ability of leptin to increase sympathetic traffic. These results demonstrate that the sympathetic nerve responses evoked by leptin emanate from leptin action on POMC neurons.
Details
- Title: Subtitle
- Abstract 036: Pomc Neurons, But Not Agrp Neurons, Are Required For Leptin-induced Sympathetic Activation
- Creators
- Balyssa Bell - Univ of Iowa, Iowa City, IAShannon HarlanDonald MorganKamal Rahmouni
- Resource Type
- Abstract
- Publication Details
- Hypertension (Dallas, Tex. 1979), Vol.64(Suppl_1), pp.A036-A036
- Publisher
- American Heart Association, Inc
- DOI
- 10.1161/hyp.64.suppl_1.036
- ISSN
- 0194-911X
- eISSN
- 1524-4563
- Language
- English
- Date published
- 11/2014
- Academic Unit
- Neuroscience and Pharmacology; Internal Medicine; Iowa Neuroscience Institute
- Record Identifier
- 9984071987802771
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