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Cardiovascular and renal profiles in rat offspring that do not undergo catch-up growth after exposure to maternal protein restriction. J Dev Orig Health Dis 2023; 14:426-436. [PMID: 36647740 DOI: 10.1017/s2040174422000666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Maternal protein restriction is often associated with structural and functional sequelae in offspring, particularly affecting growth and renal-cardiovascular function. However, there is little understanding as to whether hypertension and kidney disease occur because of a primary nephron deficit or whether controlling postnatal growth can result in normal renal-cardiovascular phenotypes. To investigate this, female Sprague-Dawley rats were fed either a low-protein (LP, 8.4% protein) or normal-protein (NP, 19.4% protein) diet prior to mating and until offspring were weaned at postnatal day (PN) 21. Offspring were then fed a non 'growth' (4.6% fat) which ensured that catch-up growth did not occur. Offspring growth was determined by weight and dual energy X-ray absorptiometry. Nephron number was determined at PN21 using the disector-fractionator method. Kidney function was measured at PN180 and PN360 using clearance methods. Blood pressure was measured at PN360 using radio-telemetry. Body weight was similar at PN1, but by PN21 LP offspring were 39% smaller than controls (Pdiet < 0.001). This difference was due to proportional changes in lean muscle, fat, and bone content. LP offspring remained smaller than NP offspring until PN360. In LP offspring, nephron number was 26% less in males and 17% less in females, than NP controls (Pdiet < 0.0004). Kidney function was similar across dietary groups and sexes at PN180 and PN360. Blood pressure was similar in LP and NP offspring at PN360. These findings suggest that remaining on a slow growth trajectory after exposure to a suboptimal intrauterine environment does not lead to the development of kidney dysfunction and hypertension.
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Ferreira ARO, Ribeiro MVG, Peres MNC, Piovan S, Gonçalves GD, Saavedra LPJ, Martins JNDL, Junior MDF, Cavalcante KVN, Lopes GKG, Carneiro M, Almeida DL, Gomes RM, Comar JF, Armitage JA, Mathias PCDF, Palma-Rigo K. Protein Restriction in the Peri-Pubertal Period Induces Autonomic Dysfunction and Cardiac and Vascular Structural Changes in Adult Rats. Front Physiol 2022; 13:840179. [PMID: 35574445 PMCID: PMC9095958 DOI: 10.3389/fphys.2022.840179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 03/22/2022] [Indexed: 11/30/2022] Open
Abstract
Perturbations to nutrition during critical periods are associated with changes in embryonic, fetal or postnatal developmental patterns that may render the offspring more likely to develop cardiovascular disease in later life. The aim of this study was to evaluate whether autonomic nervous system imbalance underpins in the long-term hypertension induced by dietary protein restriction during peri-pubertal period. Male Wistar rats were assigned to groups fed with a low protein (4% protein, LP) or control diet (20.5% protein; NP) during peri-puberty, from post-natal day (PN) 30 until PN60, and then all were returned to a normal protein diet until evaluation of cardiovascular and autonomic function at PN120. LP rats showed long-term increased mean arterial pressure (p = 0.002) and sympathetic arousal; increased power of the low frequency (LF) band of the arterial pressure spectral (p = 0.080) compared with NP animals. The depressor response to the ganglion blocker hexamethonium was increased in LP compared with control animals (p = 0.006). Pulse interval variability showed an increase in the LF band and LF/HF ratio (p = 0.062 and p = 0.048) in LP animals. The cardiac response to atenolol and/or methylatropine and the baroreflex sensitivity were similar between groups. LP animals showed ventricular hypertrophy (p = 0.044) and increased interstitial fibrosis (p = 0.028) compared with controls. Reduced protein carbonyls (PC) (p = 0.030) and catalase activity (p = 0.001) were observed in hearts from LP animals compared with control. In the brainstem, the levels of PC (p = 0.002) and the activity of superoxide dismutase and catalase (p = 0.044 and p = 0.012) were reduced in LP animals, while the levels of GSH and total glutathione were higher (p = 0.039 and p = 0.038) compared with NP animals. Protein restriction during peri-pubertal period leads to hypertension later in life accompanied by sustained sympathetic arousal, which may be associated with a disorganization of brain and cardiac redox state and structural cardiac alteration.
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Affiliation(s)
- Anna Rebeka Oliveira Ferreira
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringa, Maringa, Brazil
| | - Maiara Vanusa Guedes Ribeiro
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringa, Maringa, Brazil
| | - Maria Natalia Chimirri Peres
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringa, Maringa, Brazil
| | - Silvano Piovan
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringa, Maringa, Brazil
| | - Géssica Dutra Gonçalves
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringa, Maringa, Brazil
| | - Lucas Paulo Jacinto Saavedra
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringa, Maringa, Brazil
| | - Juliana Nunes de Lima Martins
- Laboratory of Liver Metabolism and Radioisotopes, Department of Biochemistry, State University of Maringa, Maringa, Brazil
| | - Marcos Divino Ferreira Junior
- Laboratory of Endocrine Physiology and Metabolism, Department of Physiological Sciences, Federal University of Goias, Goiania, Brazil
| | - Keilah Valeria Naves Cavalcante
- Laboratory of Endocrine Physiology and Metabolism, Department of Physiological Sciences, Federal University of Goias, Goiania, Brazil
| | - Gabriel kian Guimarães Lopes
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringa, Maringa, Brazil
| | - Mariane Carneiro
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringa, Maringa, Brazil
| | - Douglas Lopes Almeida
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringa, Maringa, Brazil
| | - Rodrigo Mello Gomes
- Laboratory of Endocrine Physiology and Metabolism, Department of Physiological Sciences, Federal University of Goias, Goiania, Brazil
| | - Jurandir Fernando Comar
- Laboratory of Liver Metabolism and Radioisotopes, Department of Biochemistry, State University of Maringa, Maringa, Brazil
| | | | - Paulo Cezar de Freitas Mathias
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringa, Maringa, Brazil
| | - Kesia Palma-Rigo
- Laboratory of Secretion Cell Biology, Department of Biotechnology, Genetics and Cell Biology, State University of Maringa, Maringa, Brazil
- Adventist College of Parana, Ivatuba, Brazil
- *Correspondence: Kesia Palma-Rigo,
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Sata Y, Burke SL, Eikelis N, Watson AMD, Gueguen C, Jackson KL, Lambert GW, Lim K, Denton KM, Schlaich MP, Head GA. Renal Deafferentation Prevents Progression of Hypertension and Changes to Sympathetic Reflexes in a Rabbit Model of Chronic Kidney Disease. Hypertension 2021; 78:1310-1321. [PMID: 34538104 DOI: 10.1161/hypertensionaha.121.17037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Yusuke Sata
- Neuropharmacology Laboratory (Y.S., S.L.B., A.M.D.W., C.G., K.L.J., K.L., G.A.H.), Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Human Neurotransmitters Laboratory (Y.S., M.P.S., G.W.L., N.E.), Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Faculty of Medicine, Nursing and Health Sciences, Central Clinical School (Y.S.), Monash University, Melbourne, VIC, Australia.,Department of Cardiology, Alfred Hospital, Melbourne, VIC, Australia (Y.S.)
| | - Sandra L Burke
- Neuropharmacology Laboratory (Y.S., S.L.B., A.M.D.W., C.G., K.L.J., K.L., G.A.H.), Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
| | - Nina Eikelis
- Human Neurotransmitters Laboratory (Y.S., M.P.S., G.W.L., N.E.), Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Iverson Health Innovation Research Institute and School of Health Sciences, Swinburne University of Technology, Hawthorn, VIC, Australia (N.E., G.W.L.)
| | - Anna M D Watson
- Neuropharmacology Laboratory (Y.S., S.L.B., A.M.D.W., C.G., K.L.J., K.L., G.A.H.), Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Department of Diabetes, Central Clinical School (A.M.D.W.), Monash University, Melbourne, VIC, Australia
| | - Cindy Gueguen
- Neuropharmacology Laboratory (Y.S., S.L.B., A.M.D.W., C.G., K.L.J., K.L., G.A.H.), Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
| | - Kristy L Jackson
- Neuropharmacology Laboratory (Y.S., S.L.B., A.M.D.W., C.G., K.L.J., K.L., G.A.H.), Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences (K.L.J), Monash University, Melbourne, VIC, Australia
| | - Gavin W Lambert
- Human Neurotransmitters Laboratory (Y.S., M.P.S., G.W.L., N.E.), Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Iverson Health Innovation Research Institute and School of Health Sciences, Swinburne University of Technology, Hawthorn, VIC, Australia (N.E., G.W.L.)
| | - Kyungjoon Lim
- Neuropharmacology Laboratory (Y.S., S.L.B., A.M.D.W., C.G., K.L.J., K.L., G.A.H.), Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Department of Physiology, Anatomy and Microbiology, La Trobe University, Melbourne, VIC, Australia (K.L.)
| | - Kate M Denton
- Cardiovascular Program, Monash Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, VIC, Australia (K.M.D.)
| | - Markus P Schlaich
- Human Neurotransmitters Laboratory (Y.S., M.P.S., G.W.L., N.E.), Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Departments of Cardiology and Nephrology, Dobney Hypertension Centre, School of Medicine, Royal Perth Hospital Unit, University of Western Australia, Royal Perth Hospital (M.P.S.)
| | - Geoffrey A Head
- Neuropharmacology Laboratory (Y.S., S.L.B., A.M.D.W., C.G., K.L.J., K.L., G.A.H.), Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Department of Pharmacology (G.A.H.), Monash University, Melbourne, VIC, Australia
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Aguilar-Roblero R, González-Mariscal G. Behavioral, neuroendocrine and physiological indicators of the circadian biology of male and female rabbits. Eur J Neurosci 2018; 51:429-453. [PMID: 30408249 DOI: 10.1111/ejn.14265] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Revised: 10/17/2018] [Accepted: 10/25/2018] [Indexed: 12/20/2022]
Abstract
Adult rabbits show robust circadian rhythms of: nursing, food and water intake, hard faeces excretion, locomotion, body temperature, blood and intraocular pressure, corticosteroid secretion, and sleep. Control of several circadian rhythms involves a light-entrained circadian clock and a food-entrained oscillator. Nursing periodicity, however, relies on a suckling stimulation threshold. Brain structures regulating this activity include the paraventricular nucleus and preoptic area, as determined by lesions and quantification of cFOS- and PER1 clock gene-immunoreactive proteins. Melatonin synthesis in the rabbit pineal gland shows a diurnal rhythm, with highest values at night and lowest ones during the day. In kits the main zeitgeber is milk intake, which synchronizes locomotor activity, body temperature, and corticosterone secretion. Brain regions involved in these effects include the median preoptic nucleus and several olfactory structures. As models for particular human illnesses rabbits have been valuable for studying glaucoma and cardiovascular disease. Circadian variations in intraocular pressure (main risk factor for glaucoma) have been found, with highest values at night, which depend on sympathetic innervation. Rabbits fed a high fat diet develop cholesterol plaques and high blood pressure, as do humans, and such increased fat intake directly modulates cardiovascular homeostasis and circadian patterns, independently of white adipose tissue accumulation. Rabbits have also been useful to investigate the characteristics of sleep across the day and its modulation by infections, cytokines and other endogenous humoral factors. Rabbit circadian biology warrants deeper investigation of the role of the suprachiasmatic nucleus in regulating most behavioral and physiological rhythms described above.
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Affiliation(s)
- Raúl Aguilar-Roblero
- División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Gabriela González-Mariscal
- Centro de Investigación en Reproducción Animal, CINVESTAV-Universidad Autónoma de Tlaxcala, Tlaxcala, Mexico
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Qian K, Feng L, Sun Y, Xiong B, Ding Y, Han P, Chen H, Chen X, Du L, Wang Y. Overexpression of Salusin- α Inhibits Vascular Intimal Hyperplasia in an Atherosclerotic Rabbit Model. BIOMED RESEARCH INTERNATIONAL 2018; 2018:8973986. [PMID: 30105261 PMCID: PMC6076935 DOI: 10.1155/2018/8973986] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Accepted: 06/27/2018] [Indexed: 11/18/2022]
Abstract
Inhibiting vascular endothelial foam is the focus of clinical attention. Using SonoVue (an ultrasound contrast agent), the salusin-α gene was transfected into the arterial intima of an atherosclerotic rabbit model induced by a high-fat diet in this study. Subsequently the model of blood lipid indexes, the pathological structure of the intima, and changes in molecules regulating atherosclerosis were investigated. The high-density lipoprotein C and apolipoprotein A values in the salusin-α gene overexpression (P) group were higher than those in the salusin-α gene interference (RP) group (P < 0.05), whereas the total cholesterol, low-density lipoprotein C, and apolipoprotein B values were reversed. Rabbits in the P group showed significantly thinner vascular intimal thickness than that of other experimental groups (P < 0.05). The expression of positive regulators of atherosclerosis (ABCA1, ABCG1) was higher in the P group than that in the RP group (P < 0.05), and the opposite effect was observed for negative regulators (ACAT1, CD36). Thus, our results showed that the overexpression of salusin-α gene inhibited the proliferation of the vascular intima, thereby throwing some light on understanding the mechanism how salusin-α gene expression interfered with the foaming of vascular intimal cells.
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Affiliation(s)
- Kun Qian
- Department of Laboratory Medicine, Hubei University of Chinese Medicine, Wuhan, Hubei, China
| | - Li Feng
- Endoscopy Center, Minhang Branch of Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yujie Sun
- Department of Laboratory Medicine, Hubei University of Chinese Medicine, Wuhan, Hubei, China
| | - Bowen Xiong
- Department of Laboratory Medicine, Hubei University of Chinese Medicine, Wuhan, Hubei, China
| | - Yi Ding
- Department of Laboratory Medicine, Hubei University of Chinese Medicine, Wuhan, Hubei, China
| | - Panting Han
- Department of Laboratory Medicine, Hubei University of Chinese Medicine, Wuhan, Hubei, China
| | - Hailun Chen
- Department of Laboratory Medicine, Hubei University of Chinese Medicine, Wuhan, Hubei, China
| | - Xiao Chen
- Department of Laboratory Medicine, Hubei University of Chinese Medicine, Wuhan, Hubei, China
| | - Ling Du
- Endoscopy Center, Minhang Branch of Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yuxue Wang
- Department of Laboratory Medicine, Hubei University of Chinese Medicine, Wuhan, Hubei, China
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Abstract
PURPOSE OF REVIEW The major health issue of being overweight or obese relates to the development of hypertension, insulin resistance and diabetic complications. One of the major underlying factors influencing the elevated blood pressure in obesity is increased activity of the sympathetic nerves to particular organs such as the kidney. RECENT FINDINGS There is now convincing evidence from animal studies that major signals such as leptin and insulin have a sympathoexcitatory action in the hypothalamus to cause hypertension. Recent studies suggest that this may involve 'neural plasticity' within hypothalamic signalling driven by central actions of leptin mediated via activation of melanocortin receptor signalling and activation of brain neurotrophic factors. This review describes the evidence to support the contribution of the SNS to obesity related hypertension and the major metabolic and adipokine signals.
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Hart EC, Head GA, Carter JR, Wallin BG, May CN, Hamza SM, Hall JE, Charkoudian N, Osborn JW. Recording sympathetic nerve activity in conscious humans and other mammals: guidelines and the road to standardization. Am J Physiol Heart Circ Physiol 2017; 312:H1031-H1051. [PMID: 28364017 DOI: 10.1152/ajpheart.00703.2016] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 03/06/2017] [Accepted: 03/06/2017] [Indexed: 01/03/2023]
Abstract
Over the past several decades, studies of the sympathetic nervous system in humans, sheep, rabbits, rats, and mice have substantially increased mechanistic understanding of cardiovascular function and dysfunction. Recently, interest in sympathetic neural mechanisms contributing to blood pressure control has grown, in part because of the development of devices or surgical procedures that treat hypertension by manipulating sympathetic outflow. Studies in animal models have provided important insights into physiological and pathophysiological mechanisms that are not accessible in human studies. Across species and among laboratories, various approaches have been developed to record, quantify, analyze, and interpret sympathetic nerve activity (SNA). In general, SNA demonstrates "bursting" behavior, where groups of action potentials are synchronized and linked to the cardiac cycle via the arterial baroreflex. In humans, it is common to quantify SNA as bursts per minute or bursts per 100 heart beats. This type of quantification can be done in other species but is only commonly reported in sheep, which have heart rates similar to humans. In rabbits, rats, and mice, SNA is often recorded relative to a maximal level elicited in the laboratory to control for differences in electrode position among animals or on different study days. SNA in humans can also be presented as total activity, where normalization to the largest burst is a common approach. The goal of the present paper is to put together a summary of "best practices" in several of the most common experimental models and to discuss opportunities and challenges relative to the optimal measurement of SNA across species.Listen to this article's corresponding podcast at https://ajpheart.podbean.com/e/guidelines-for-measuring-sympathetic-nerve-activity/.
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Affiliation(s)
- Emma C Hart
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom;
| | - Geoffrey A Head
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | | | | | - Clive N May
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | | | - John E Hall
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, Mississippi
| | - Nisha Charkoudian
- United States Army Research Institute of Environmental Medicine, Natick, Massachusetts; and
| | - John W Osborn
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota
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Differential impact of type-1 and type-2 diabetes on control of heart rate in mice. Auton Neurosci 2015; 194:17-25. [PMID: 26725752 DOI: 10.1016/j.autneu.2015.12.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 11/23/2015] [Accepted: 12/14/2015] [Indexed: 01/14/2023]
Abstract
AIMS Cardiac autonomic dysfunction is a serious complication of diabetes. One consequence is disruption of the normal beat-to-beat regulation of heart rate (HR), i.e. HR variability (HRV). However, our understanding of the disease process has been limited by inconsistent HR/HRV data from previous animal studies. We hypothesized that differences in the method of measurement, time of day, and level of stress account for the differing results across studies. Thus, our aim was to systematically assess HR and HRV in two common diabetic mouse models. METHODS ECG radiotelemetry devices were implanted into db/db (type-2 diabetic), STZ-treated db/+ (type-1 diabetic), and control db/+ mice (n=4 per group). HR and HRV were analyzed over 24 h and during treadmill testing. RESULTS 24 h analysis revealed that db/db mice had an altered pattern of circadian HR changes, and STZ-treated mice had reduced HR throughout. HRV measures linked to sympathetic control were reduced in db/db mice in the early morning and early afternoon, and partially reduced in STZ-treated mice. HR response to treadmill testing was blunted in both models. CONCLUSIONS It is important to consider both time of day and level of stress when assessing HR and HRV in diabetic mice. db/db mice may have altered circadian rhythm of sympathetic control of HR, whereas STZ-treated mice have a relative reduction. This study provides baseline data and a framework for HR analysis that may guide future investigations.
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Barzel B, Lim K, Burke SL, Armitage JA, Head GA. Specific role of dietary fat in modifying cardiovascular and locomotor activity 24-h rhythms. Chronobiol Int 2015; 32:668-76. [PMID: 26035483 DOI: 10.3109/07420528.2015.1032414] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Meal-fed conscious rabbits normally exhibit postprandial elevation in blood pressure, heart rate (HR) and locomotor activity, which is abolished by consumption of a high-fat diet (HFD). Here, we assessed whether the cardiovascular changes are attributable to the increased caloric intake due to greater fat content or to hyperphagia. Rabbits were meal-fed during the baseline period then maintained on either an ad libitum normal fat diet (NFD) or ad libitum HFD for 2 weeks. Blood pressure, HR and locomotor activity were measured daily by radio-telemetry alongside food intake and body weight. Caloric intake in rabbits given a NFD ad libitum rose 50% from baseline but there were no changes in cardiovascular parameters. By contrast, HR increased by 10% on the first day of the ad libitum HFD (p < 0.001) prior to any change in body weight while blood pressure increased 7% after 4 d (p < 0.01) and remained elevated. Baseline 24-h patterns of blood pressure and HR were closely associated with mealtime, characterised by afternoon peaks and morning troughs. When the NFD was changed from meal-fed to ad libitum, blood pressure and HR did not change but afternoon activity levels decreased (p < 0.05). By contrast, after 13 d ad libitum HFD, morning HR, blood pressure and activity increased by 20%, 8% and 71%, respectively. Increased caloric intake specifically from fat, but not as a result of hyperphagia, appears to directly modulate cardiovascular homeostasis and circadian patterns, independent of white adipose tissue accumulation.
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Affiliation(s)
- Benjamin Barzel
- Neuropharmacology Laboratory, Baker IDI Heart and Diabetes Institute , Melbourne, Victoria , Australia
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Head GA, Lim K, Barzel B, Burke SL, Davern PJ. Central nervous system dysfunction in obesity-induced hypertension. Curr Hypertens Rep 2015; 16:466. [PMID: 25090962 DOI: 10.1007/s11906-014-0466-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The activation of the sympathetic nervous system is a major mechanism underlying both human and experimental models of obesity-related hypertension. While insulin and the adipokine leptin have long been thought to contribute to obesity-related neurogenic mechanisms, the evidence is now very strong that they play a major role, shown particularly in animal studies using selective receptor antagonists. There is not just maintenance of leptin's sympatho-excitatory actions as previously suggested but considerable amplification particularly in renal sympathetic nervous activity. Importantly, these changes are not dependent on short-term elevation or reduction in plasma leptin or insulin, but require some weeks to develop indicating a slow "neural adaptivity" within hypothalamic signalling. These effects can be carried across generations even when offspring are raised on a normal diet. A better understanding of the underlying mechanism should be a high research priority given the prevalence of obesity not just in the current population but also for future generations.
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Affiliation(s)
- Geoffrey A Head
- Neuropharmacology Laboratory, Baker IDI Heart and Diabetes Institute, P.O. Box 6492, Melbourne, Victoria, 3004, Australia,
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11
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Barzel B, Weir JM, Meikle PJ, Burke SL, Armitage JA, Head GA. Short term fat feeding rapidly increases plasma insulin but does not result in dyslipidaemia. Front Physiol 2014; 5:469. [PMID: 25520669 PMCID: PMC4251291 DOI: 10.3389/fphys.2014.00469] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 11/15/2014] [Indexed: 11/29/2022] Open
Abstract
Although the association between obesity and hypertension is well-known, the underlying mechanism remains elusive. Previously, we have shown that 3 week fat feeding in rabbits produces greater visceral adiposity, hypertension, tachycardia and elevated renal sympathetic nerve activity (RSNA) compared to rabbits on a normal diet. Because hyperinsulinaemia, hyperleptinemia, and dyslipidaemia are independent cardiovascular risk factors associated with hypertension we compared plasma insulin, leptin, and lipid profiles in male New Zealand White rabbits fed a normal fat diet (NFD 4.3% fat, n = 11) or high fat diet (HFD 13.4% fat, n = 13) at days 1, 2, 3 and weeks 1, 2, 3 of the diet. Plasma concentrations of diacylglyceride (DG), triacylglyceride (TG), ceramide and cholesteryl esters (CE) were obtained after analysis by liquid chromatography mass spectrometry. Plasma insulin and glucose increased within the first 3 days of the diet in HFD rabbits (P < 0.05) and remained elevated at week 1 (P < 0.05). Blood pressure and heart rate (HR) followed a similar pattern. By contrast, in both groups, plasma leptin levels remained unchanged during the first few days (P > 0.05), increasing by week 3 in fat fed animals alone (P < 0.05). Concentrations of total DG, TG, CE, and Ceramide at week 3 did not differ between groups (P > 0.05). Our data show plasma insulin increases rapidly following consumption of a HFD and suggests that it may play a role in the rapid rise of blood pressure. Dyslipidaemia does not appear to contribute to the hypertension in this animal model.
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Affiliation(s)
- Benjamin Barzel
- Neuropharmacology Laboratory, BakerIDI Heart and Diabetes Institute Melbourne, VIC, Australia ; Department of Anatomy and Developmental Biology, Monash University Melbourne, VIC, Australia
| | - Jacquelyn M Weir
- Neuropharmacology Laboratory, BakerIDI Heart and Diabetes Institute Melbourne, VIC, Australia
| | - Peter J Meikle
- Neuropharmacology Laboratory, BakerIDI Heart and Diabetes Institute Melbourne, VIC, Australia
| | - Sandra L Burke
- Neuropharmacology Laboratory, BakerIDI Heart and Diabetes Institute Melbourne, VIC, Australia
| | - James A Armitage
- Neuropharmacology Laboratory, BakerIDI Heart and Diabetes Institute Melbourne, VIC, Australia ; Department of Anatomy and Developmental Biology, Monash University Melbourne, VIC, Australia ; School of Medicine (Optometry), Deakin University Geelong, VIC, Australia
| | - Geoffrey A Head
- Neuropharmacology Laboratory, BakerIDI Heart and Diabetes Institute Melbourne, VIC, Australia ; Department of Pharmacology, Monash University Melbourne, VIC, Australia
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Prior LJ, Davern PJ, Burke SL, Lim K, Armitage JA, Head GA. Exposure to a High-Fat Diet During Development Alters Leptin and Ghrelin Sensitivity and Elevates Renal Sympathetic Nerve Activity and Arterial Pressure in Rabbits. Hypertension 2014; 63:338-45. [DOI: 10.1161/hypertensionaha.113.02498] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Larissa J. Prior
- From the Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia (L.J.P., P.J.D., S.L.B., K.L., J.A.A., G.A.H.); School of Medicine (Optometry), Deakin University, Waurn Ponds, Victoria, Australia (J.A.A.); and Department of Pharmacology, Monash University, Clayton, Victoria, Australia (G.A.H.)
| | - Pamela J. Davern
- From the Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia (L.J.P., P.J.D., S.L.B., K.L., J.A.A., G.A.H.); School of Medicine (Optometry), Deakin University, Waurn Ponds, Victoria, Australia (J.A.A.); and Department of Pharmacology, Monash University, Clayton, Victoria, Australia (G.A.H.)
| | - Sandra L. Burke
- From the Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia (L.J.P., P.J.D., S.L.B., K.L., J.A.A., G.A.H.); School of Medicine (Optometry), Deakin University, Waurn Ponds, Victoria, Australia (J.A.A.); and Department of Pharmacology, Monash University, Clayton, Victoria, Australia (G.A.H.)
| | - Kyungjoon Lim
- From the Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia (L.J.P., P.J.D., S.L.B., K.L., J.A.A., G.A.H.); School of Medicine (Optometry), Deakin University, Waurn Ponds, Victoria, Australia (J.A.A.); and Department of Pharmacology, Monash University, Clayton, Victoria, Australia (G.A.H.)
| | - James A. Armitage
- From the Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia (L.J.P., P.J.D., S.L.B., K.L., J.A.A., G.A.H.); School of Medicine (Optometry), Deakin University, Waurn Ponds, Victoria, Australia (J.A.A.); and Department of Pharmacology, Monash University, Clayton, Victoria, Australia (G.A.H.)
| | - Geoffrey A. Head
- From the Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia (L.J.P., P.J.D., S.L.B., K.L., J.A.A., G.A.H.); School of Medicine (Optometry), Deakin University, Waurn Ponds, Victoria, Australia (J.A.A.); and Department of Pharmacology, Monash University, Clayton, Victoria, Australia (G.A.H.)
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