Abstract MP17: Time Restricted Feeding Improves Cardiovascular Rhythms And Vascular Metabolism In Mice On A Chronic High Fat Diet

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Paramita Pati ◽  
Dingguo Zhang ◽  
Jackson Colson ◽  
Shannon M Bailey ◽  
Karen L Gamble ◽  
...  

Irregular timing of food intake increases hypertension and cardiometabolic disease risk. A chronic high fat diet (HFD) also disrupts circadian rhythms. We hypothesized that active period time restricted feeding (TRF) during the last 2 weeks in mice on a chronic HFD will improve blood pressure rhythm, diurnal variation of circulating plasma factors, and vascular metabolism. Mice (male 8-week old, C57BL/6J) were fed a normal diet (ND; 10% fat) or HFD (45% fat) for 20 weeks ad libitum. For the final 2 weeks, half of the HFD mice were subjected to TRF. Mean arterial pressure (MAP), heart rate (HR), and locomotor activity were assessed by telemetry. TRF significantly increased the active-inactive period difference in MAP and HR in in mice fed a HFD (ΔMAP: ND: 16±0.7 mmHg, HFD: 15±0.8 mmHg, HFD+TRF: 18±0.9 mmHg, n=6-8, p=0.01; ΔHR: ND: 68±5.1 bpm, HFD: 69±6.5 bpm, HFD+TRF: 113±7.9 bpm, n=6-8, p<0.01). Diurnal changes in locomotor activity are not different between groups. At the end of the study, plasma was collected at 4 hour intervals over a 24 hour period (ZT0 at 7AM; ZT12 at 7PM). Circulating levels of liver-derived mediators β-hydroxybutyrate (βHB) and insulin-like growth factor-1 (IGF-1) showed significant differences due to diet but not TRF (βHB, ZT21: ND: 0.16±0.01 mM, HFD: 0.20±0.02 mM, HFD+TRF: 0.19±0.01 mM, n=5-6, p=0.02; IGF-1, ZT5: ND: 232±18 ng/mL, HFD: 292±34 ng/mL , HFD+TRF: 371±14 ng/mL, n=5-6, p<0.01). Plasma leptin was significantly higher in mice on HFD and reduced by TRF at ZT12 (ND: 5.3±1.3 ng/mL, HFD: 22.5±2.9 ng/mL, HFD+TRF: 10.3±3.5ng/mL, n=5-6, p<0.01) and ZT17 (ND: 6.7±1.1 ng/mL, HFD: 32.5±3.0 ng/mL, HFD+TRF: 25.0±1.3 ng/mL, n=5-6, p<0.01). Plasma adiponectin was unchanged between all groups. TRF in HFD mice increased NAD + , important for metabolism, in renal vessels at ZT17 (HFD: 0.10±0.02 pmol/μg; HFD+TRF: 0.19±0.03 pmol/μg; n=5, p=0.03). Aortic NAD + at ZT1 was not affected by TRF in HFD mice (HFD: 1.83±0.35 pmol/μg, HFD+TRF: 1.35±0.35 pmol/μg, n=4, p=0.37). Our results indicate that TRF in mice on HFD increases the active-inactive period difference in MAP and HR and alters plasma metabolites, suggesting the timing of food intake on a chronic HFD improves cardiovascular rhythms with increased renal vascular metabolism and reduced leptin levels.

2010 ◽  
Vol 299 (4) ◽  
pp. R1082-R1090 ◽  
Author(s):  
Jill K. Morris ◽  
Gregory L. Bomhoff ◽  
John A. Stanford ◽  
Paige C. Geiger

Despite numerous clinical studies supporting a link between type 2 diabetes (T2D) and Parkinson's disease (PD), the clinical literature remains equivocal. We, therefore, sought to address the relationship between insulin resistance and nigrostriatal dopamine (DA) in a preclinical animal model. High-fat feeding in rodents is an established model of insulin resistance, characterized by increased adiposity, systemic oxidative stress, and hyperglycemia. We subjected rats to a normal chow or high-fat diet for 5 wk before infusing 6-hydroxydopamine (6-OHDA) into the medial forebrain bundle. Our goal was to determine whether a high-fat diet and the resulting peripheral insulin resistance would exacerbate 6-OHDA-induced nigrostriatal DA depletion. Prior to 6-OHDA infusion, animals on the high-fat diet exhibited greater body weight, increased adiposity, and impaired glucose tolerance. Two weeks after 6-OHDA, locomotor activity was tested, and brain and muscle tissue was harvested. Locomotor activity did not differ between the groups nor did cholesterol levels or measures of muscle atrophy. High-fat-fed animals exhibited higher homeostatic model assessment of insulin resistance (HOMA-IR) values and attenuated insulin-stimulated glucose uptake in fast-twitch muscle, indicating decreased insulin sensitivity. Animals in the high-fat group also exhibited greater DA depletion in the substantia nigra and the striatum, which correlated with HOMA-IR and adiposity. Decreased phosphorylation of HSP27 and degradation of IκBα in the substantia nigra indicate increased tissue oxidative stress. These findings support the hypothesis that a diet high in fat and the resulting insulin resistance may lower the threshold for developing PD, at least following DA-specific toxin exposure.


2020 ◽  
Vol 11 (4) ◽  
pp. 347-359
Author(s):  
D. Valent ◽  
L. Arroyo ◽  
E. Fàbrega ◽  
M. Font-i-Furnols ◽  
M. Rodríguez-Palmero ◽  
...  

The pig is a valuable animal model to study obesity in humans due to the physiological similarity between humans and pigs in terms of digestive and associated metabolic processes. The dietary use of vegetal protein, probiotics and omega-3 fatty acids is recommended to control weight gain and to fight obesity-associated metabolic disorders. Likewise, there are recent reports on their beneficial effects on brain functions. The hypothalamus is the central part of the brain that regulates food intake by means of the production of food intake-regulatory hypothalamic neuropeptides, as neuropeptide Y (NPY), orexin A and pro-opiomelanocortin (POMC), and neurotransmitters, such as dopamine and serotonin. Other mesolimbic areas, such as the hippocampus, are also involved in the control of food intake. In this study, the effect of a high fat diet (HFD) alone or supplemented with these additives on brain neuropeptides and neurotransmitters was assessed in forty-three young pigs fed for 10 weeks with a control diet (T1), a high fat diet (HFD, T2), and HFD with vegetal protein supplemented with Bifidobacterium breve CECT8242 alone (T3) or in combination with omega-3 fatty acids (T4). A HFD provoked changes in regulatory neuropeptides and 3,4-dihydroxyphenylacetic acid (DOPAC) in the hypothalamus and alterations mostly in the dopaminergic system in the ventral hippocampus. Supplementation of the HFD with B. breve CECT8242, especially in combination with omega-3 fatty acids, was able to partially reverse the effects of HFD. Correlations between productive and neurochemical parameters supported these findings. These results confirm that pigs are an appropriate animal model alternative to rodents for the study of the effects of HFD on weight gain and obesity. Furthermore, they indicate the potential benefits of probiotics and omega-3 fatty acids on brain function.


2020 ◽  
Vol 215 ◽  
pp. 112773 ◽  
Author(s):  
Harish S. Appiakannan ◽  
Melissa L. Rasimowicz ◽  
Christopher B. Harrison ◽  
E. Todd Weber

2000 ◽  
Vol 279 (1) ◽  
pp. R230-R238 ◽  
Author(s):  
Clayton E. Mathews ◽  
Kathie Wickwire ◽  
Wiliam P. Flatt ◽  
Carolyn D. Berdanier

The hypothesis that BHE/Cdb rats with mutations in their mitochondrial genome might accommodate this mutation by changing their food intake patterns was tested. Four experiments were conducted. Experiments 1 and 2examined food intake patterns of BHE/Cdb rats fed a stock diet or BHE/Cdb and Sprague-Dawley rats fed a high-fat diet from weaning. Experiment 3 examined the daily rhythms of respiration and heat production in these rats at 200 days of age. Experiment 4 examined the effects of diet composition on these measurements at 50-day intervals. The Sprague-Dawley rats, regardless of diet, had the typical day-night rhythms of feeding and respiration. In contrast, the BHE/Cdb rats fed the high-fat diet showed normal rhythms initially, but with age, these rhythms were attenuated. The changes in rhythms preceded the development of glucose intolerance.


2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Alireza Jahan-Mihan ◽  
Kea Schwarz ◽  
Leila Nynia ◽  
Tatyana Kimble

Abstract Objectives The objective of this study was to investigate the main and interactive effects of fat and sodium content of the diet on food intake, body weight and composition, glucose metabolism and blood pressure in male Wistar rats. Methods Male Wistar Rats (n = 48, initial body weight: 115.30 ± 1.73 g) were allocated into 4 groups (n = 12/group) and received one of the following diets: Normal sodium normal fat (NSNF), normal sodium high fat (NSHF), high sodium normal fat (HSNF), high sodium high fat (HSHF) diet for 12 weeks. Body weight (BW) and food intake (FI) were measured weekly. Short-term food intake (1, 2 and 12 hours food intake after 12 hours fasting) was measured at week 6. Body composition and organs’ weight were measured at week 12. Systolic (SBP) and diastolic (DBP) blood pressure, pulse and fasting blood glucose (FBG) were measured and oral glucose tolerance test (OGTT) was conducted at weeks 1, 4, 8 and 12. Results Regardless of sodium content, a greater FI (both gram and cal) was observed in rats fed normal fat diet compared with those fed high fat diet. Consistently, FI (g) at 1, 2 and 12 hours was higher in rats fed a normal fat diet. However, no difference in calorie intake was observed at any time point. Higher BW and fat (%) was observed in high fat diet groups. Moreover, greater kidneys’ weights was observed in high sodium diet groups. Fasting blood glucose was higher in rats fed a normal sodium diet compared with those fed a high sodium diet while the tAUC glucose response to glucose preload was higher in rats fed a high fat diet compared with those fed a normal fat diet which is consistent with higher body weight in high fat diet groups. Regardless of fat content of the diet, pulse was higher in rats fed a high sodium diet compared with those fed a normal sodium diet. No effect of either dietary sodium or fat content of the diet on SBP or DBP was observed. Conclusions Fat but not sodium content of the diet is a determining factor in regulation of FI and BW. Moreover, both fat and sodium content of the diet influence the glucose metabolism potentially through different mechanisms. While pulse is influenced by sodium content, the results of this study do not support the effect of sodium or fat content of the diet on either SBP or DBP. Funding Sources UNF, Brooks College of Health internal grant.


2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Bret Rust ◽  
Aaron Mehus ◽  
Joseph Idso ◽  
Matthew Picklo

Abstract Objectives Obesity and obesity-related disease contribute to health care costs and pose serious health risks. Rodent studies indicate that time-restricted feeding (TRF) may be effective in reducing adiposity and metabolic disease associated with obesity. However, the metabolic pathways impacted by TRF in the context of obesogenic, high-fat (HF) diets need clarity. In the present work we examined the metabolomic changes in plasma induced by TRF of a HF diet in mice compared to a HF diet eaten ad libitum (AL) vs AL intake of a low-fat (LF) control diet. Methods Male mice (12 weeks old) were fed a LF-AL diet (16%en fat), a HF-AL diet (48%en fat) or a HF diet restricted to feeding for 12 hours per day during the dark phase (HF-TRF). In week 9 of the study, energy expenditure data were collected. After 12 weeks, animals were fasted and plasma collected for clinical chemistries and metabolomic analysis. Multivariate analysis was used to discriminate diet treatments in untargeted metabolomic data. Results Energy expenditure measurements throughout the day showed a markedly reduced fasting respiratory exchange ratio (RER) in HF-TRF mice during the inactive (light) phase compared to AL groups. Measures of insulin resistance, while increased with HF-AL intake, were resolved in the HF-TRF group. Partial least squares discriminant analysis revealed plasma non-esterified fatty acids (NEFA) and amino acids (AA) to be important discriminators between diet treatments. TRF resulted in elevated NEFA concentrations of the saturated fatty acids (12:0 to 18:0) and the polyunsaturated fatty acids α-linolenic acid and linoleic acid compared to HF-AL. Conversely, the concentrations of aromatic and branched chain amino acids were reduced in HF-TRF mice compared to HF-AL mice. Conclusions Alterations in plasma metabolites following TRF of a HF diet are consistent with greater lipid utilization during the inactive phase as reflected in the RER. Decreases in the aromatic and branched chain amino acid concentrations are consistent with improved insulin sensitivity in humans. Funding Sources This work was supported by USDA-ARS project 3062-51000-053-00D. Supporting Tables, Images and/or Graphs


2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Wycliffe Makori Arika ◽  
Cromwell Mwiti Kibiti ◽  
Joan Murugi Njagi ◽  
Mathew Piero Ngugi

Obesity is the main component of metabolic syndromes involving distinct etiologies that target different underlying behavioral and physiological functions within the brain structures and neuronal circuits. An alteration in the neuronal circuitry stemming from abdominal or central obesity stimulates a cascade of changes in neurochemical signaling that directly or indirectly mediate spontaneously emitted behaviors such as locomotor activity patterns, anxiety, and exploration. Pharmacological agents available for the treatment of neurologic disorders have been associated with limited potency and intolerable adverse effects. These have necessitated the upsurge in the utilization of herbal prescriptions due to their affordability and easy accessibility and are firmly embedded within wider belief systems of many people. Gnidia glauca has been used in the management of many ailments including obesity and associated symptomatic complications. However, its upsurge in use has not been accompanied by empirical determination of these folkloric claims. The present study, therefore, is aimed at determining the modulatory effects of dichloromethane leaf extract of Gnidia glauca on locomotor activity, exploration, and anxiety-like behaviors in high-fat diet-induced obese rats in an open-field arena. Obesity was experimentally induced by feeding the rats with prepared high-fat diet and water ad libitum for 6 weeks. The in vivo antiobesity effects were determined by oral administration of G. glauca at dosage levels of 200, 250, and 300 mg/kg body weight in high-fat diet-induced obese rats from the 6th to 12th week. Phytochemical analysis was done using gas chromatography linked to mass spectroscopy. Results indicated that Gnidia glauca showed anxiolytic effects and significantly increased spontaneous locomotor activity and exploration-like behaviors in HFD-induced obese rats. The plant extract also contained phytocompounds that have been associated with amelioration of the main neurodegenerative mediators, viz., inflammation and oxidative stress. These findings provide “qualified leads” for the synthesis of new alternative therapeutic agents for the management of neurologic disorders. However, there is a need to conduct toxicity studies of Gnidia glauca to establish its safety profiles.


2001 ◽  
Vol 280 (2) ◽  
pp. R504-R509 ◽  
Author(s):  
L. Lin ◽  
R. Martin ◽  
A. O. Schaffhauser ◽  
D. A. York

Dietary induced obesity in rodents is associated with a resistance to leptin. We have investigated the hypothesis that dietary fat per se alters the feeding response to peripheral leptin in rats that were fed either their habitual high- or low-fat diet or were naively exposed to the alternative diet. Osborne-Mendel rats were adapted to either high- or low-fat diet. Food-deprived rats were given either leptin (0.5 mg/kg body wt ip) or saline, after which they were provided with either their familiar diet or the alternative diet. Food intake of rats adapted and tested with the low-fat diet was reduced 4 h after leptin injection, whereas rats adapted and tested with a high-fat diet did not respond to leptin. Leptin was injected again 1 and 5 days after the high-fat diet-adapted rats were switched to the low-fat diet. Leptin reduced the food intake on both days. In contrast, when low-fat diet-adapted rats were switched to a high-fat diet, the leptin inhibitory response was present on day 1 but not observed on day 5. Peripheral injection of leptin increased serum corticosterone level and decreased hypothalamic neuropeptide Y mRNA expression in rats fed the low-fat but not the high-fat diet for 20 days. The data suggest that dietary fat itself, rather than obesity, may induce leptin resistance within a short time of exposure to a high-fat diet.


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