File(s) under permanent embargo
Reduced preprandial dipping accounts for rapid elevation of blood pressure and renal sympathetic nerve activity in rabbits fed a high-fat diet
journal contribution
posted on 2013-06-01, 00:00 authored by S Burke, L Prior, E Lukoshkova, K Lim, B Barzel, P Davern, James ArmitageJames Armitage, G HeadConsumption of a high-fat diet (HFD) by rabbits results in increased blood pressure (BP), heart rate (HR), and renal sympathetic nerve activity (RSNA) within 1 wk. Here, we determined how early this activation occurred and whether it was related to changes in cardiovascular and neural 24-h rhythms. Rabbits were meal-fed a HFD for 3 wks, then a normal-fat diet (NFD) for 1 wk. BP, HR, and RSNA were measured daily in the home cage via implanted telemeters. Baseline BP, HR, and RSNA over 24 h were 71 ± 1 mm Hg, 205 ± 4 beats/min and 7 ± 1 normalized units (nu). The 24-h pattern was entrained to the feeding cycle and values increased from preprandial minimum to postprandial maximum by 4 ± 1 mm Hg, 51 ± 6 beats/min, and 1.6 ± .6 nu each day. Feeding of a HFD markedly diminished the preprandial dip after 2 d (79–125% of control; p < 0.05) and this reduction lasted for 3 wks of HFD. Twenty-four-hour BP, HR, and RSNA concurrently increased by 2%, 18%, and 22%, respectively. Loss of preprandial dipping accounted for all of the BP increase and 50% of the RSNA increase over 3 wks and the 24-h rhythm became entrained to the light-dark cycle. Resumption of a NFD did not alter the BP preprandial dip. Thus, elevated BP induced by a HFD and mediated by increased sympathetic nerve activity results from a reduction in preprandial dipping, from the first day. Increased calories, glucose, insulin, and leptin may account for early changes, whereas long-term loss of dipping may be related to increased sensitivity of sympathetic pathways.
History
Journal
Chronobiology internationalVolume
30Issue
5Pagination
726 - 738Publisher
Informa HealthcareLocation
London, EnglandPublisher DOI
ISSN
0742-0528eISSN
1525-6073Language
engPublication classification
C1 Refereed article in a scholarly journalUsage metrics
Categories
No categories selectedKeywords
24-hour rhythmblood pressureheart rateobesityrabbitssympathetic nervous systemScience & TechnologyLife Sciences & BiomedicineBiologyPhysiologyLife Sciences & Biomedicine - Other TopicsHEART-RATEARTERIAL-PRESSURECARDIOVASCULAR-RESPONSESHYPERTENSIVE PATIENTSCIRCADIAN-RHYTHMSWEIGHT-LOSSLEPTINGHRELINMETABOLISM
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC