scholarly journals The effects of exercise and diet on olfactory capability in detection dogs

2014 ◽  
Vol 3 ◽  
Author(s):  
Craig T. Angle ◽  
Joseph J. Wakshlag ◽  
Robert L. Gillette ◽  
Todd Steury ◽  
Pamela Haney ◽  
...  

AbstractA previous work suggests that dietary fat may influence canine olfaction. The present study evaluated whether olfactory performance could be influenced by forms of dietary fat and exercise. Seventeen certified detection dogs were fed three different diets (high fat, low fat or high polyunsaturated fat) for 12 weeks. After 12 weeks, olfactory testing was performed using a scent wheel in an olfaction laboratory using three explosive materials. The dogs completed eight to twelve scent trials before and after a 30 min treadmill exercise on five consecutive days. A mixed-effect logistic regression model was used to examine how diet, pre- or post-exercise, trial number, odourant, mass of target and target position influenced the probability of dogs alerting on the target odour. There were no significant changes in the dog's ability to find a target odour at threshold amounts. Dogs were 1·42 (1·08, 1·87; 95 % CI) times as likely to find a target on the high polyunsaturated fat diet relative to the high-fat diet (P = 0·009). The low-fat diet was not significantly different from either the high-fat diet or the high polyunsaturated fat diet (P = 0·12). Dogs were 1·49 (1·26, 1·76; 95 % CI) times as likely to find a target prior to exercise relative to after exercise (P < 0·001). Dogs on the high PUFA diet utilising maize oil showed mild improvement in olfaction. The exact reasons are unknown; however, the higher relative amount of linoleic acid in the diet may play a role in olfactory sensation which warrants further examination of optimal diets for detection dogs.

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.


2016 ◽  
Vol 310 (11) ◽  
pp. E886-E899 ◽  
Author(s):  
Pia Kiilerich ◽  
Lene Secher Myrmel ◽  
Even Fjære ◽  
Qin Hao ◽  
Floor Hugenholtz ◽  
...  

Female C57BL/6J mice were fed a regular low-fat diet or high-fat diets combined with either high or low protein-to-sucrose ratios during their entire lifespan to examine the long-term effects on obesity development, gut microbiota, and survival. Intake of a high-fat diet with a low protein/sucrose ratio precipitated obesity and reduced survival relative to mice fed a low-fat diet. By contrast, intake of a high-fat diet with a high protein/sucrose ratio attenuated lifelong weight gain and adipose tissue expansion, and survival was not significantly altered relative to low-fat-fed mice. Our findings support the notion that reduced survival in response to high-fat/high-sucrose feeding is linked to obesity development. Digital gene expression analyses, further validated by qPCR, demonstrated that the protein/sucrose ratio modulated global gene expression over time in liver and adipose tissue, affecting pathways related to metabolism and inflammation. Analysis of fecal bacterial DNA using the Mouse Intestinal Tract Chip revealed significant changes in the composition of the gut microbiota in relation to host age and dietary fat content, but not the protein/sucrose ratio. Accordingly, dietary fat rather than the protein/sucrose ratio or adiposity is a major driver shaping the gut microbiota, whereas the effect of a high-fat diet on survival is dependent on the protein/sucrose ratio.


2016 ◽  
Vol 311 (6) ◽  
pp. E989-E997 ◽  
Author(s):  
Denise E. Lackey ◽  
Raul G. Lazaro ◽  
Pingping Li ◽  
Andrew Johnson ◽  
Angelina Hernandez-Carretero ◽  
...  

Consumption of excess calories results in obesity and insulin resistance and has been intensively studied in mice and humans. The objective of this study was to determine the specific contribution of dietary fat rather than total caloric intake to the development of obesity-associated insulin resistance. We used an intragastric feeding method to overfeed excess calories from a low-fat diet (and an isocalorically matched high-fat diet) through a surgically implanted gastric feeding tube to generate obesity in wild-type mice followed by hyperinsulinemic-euglycemic clamp studies to assess the development of insulin resistance. We show that overfeeding a low-fat diet results in levels of obesity similar to high-fat diet feeding in mice. However, despite a similar body weight, obese high-fat diet-fed mice are more insulin resistant than mice fed an isocaloric low-fat diet. Therefore, increased proportion of calories from dietary fat further potentiates insulin resistance in the obese state. Furthermore, crossover diet studies revealed that reduction in dietary fat composition improves glucose tolerance in obesity. In the context of the current obesity and diabetes epidemic, it is particularly important to fully understand the role of dietary macronutrients in the potentiation and amelioration of disease.


2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Megha Murali ◽  
Carla Taylor ◽  
Peter Zahradka ◽  
Jeffrey Wigle

Background and Objective: Arterial stiffness is recognized as being an independent predictor of incipient vascular disease associated with obesity and metabolic syndrome. In obese subjects, the decrease in the plasma level of adiponectin, an anti-diabetic and anti-atherogenic adipokine, is well known. Hence the aim of our study was to examine the effect of loss of adiponectin on the development of arterial stiffness in response to a high fat diet. Methods and Results: Male 8-week old adiponectin knockout (APN KO) and C57BL/6 (control) mice were fed a high fat diet (60% Calories from fat) for 12 weeks to induce obesity and insulin resistance (n=10/group). APN KO and C57BL/6 mice were fed a low fat diet (10% Calories from fat) and used as lean controls (n=10/group). After 12 weeks on the high fat diet, the APN KO mice weighed significantly more than the C57BL/6 mice (45.1±1.3 g vs 40.1±1.1 g, p=0.0008) but there was no difference in the final weights between genotypes fed the low fat diet. APN KO mice on both high and low fat diets for 12 weeks developed insulin resistance as measured by oral glucose tolerance test (Area under curve (AUC) mmol/L х min = 437±70 and 438±57) as compared to the C57BL/6 mice fed low or high fat diets (AUC mmol/L х min = 251±27 and 245±43). Arterial stiffness was determined by Doppler pulse wave velocity analysis of the femoral artery. Pulse wave velocity was increased in APN KO mice fed a high fat diet relative to those fed the low fat diet (12.56±0.78 cm/s vs 9.47±0.95 cm/s, p=0.0035; n=8-10). Pulse wave velocity was not different between C57BL/6 control mice on the low or high fat diets (10.63±0.73 cm/s and 10.86±0.50 cm/s), thus revealing that only mice deficient in adiponectin developed arterial stiffness in response to high fat diet. Conclusions: Potentiation of the vascular stiffness in diet-induced obese APN KO mice indicates that adiponectin has a role in modulating vascular structure and the APN KO mouse models the vascular changes that occur in human obesity and metabolic disorders. Morphometric analysis of the aortic tissues for vessel thickness and expression of extracellular proteins will further validate the potential role of adiponectin on the maintenance of arterial elasticity in addition to its known effect on eNOS mediated vasoprotection.


2018 ◽  
Vol 16 ◽  
pp. 205873921876094 ◽  
Author(s):  
Gang Yu ◽  
Lili Zhu ◽  
Haiyan Li ◽  
Youyou Shao ◽  
Lei Chong ◽  
...  

Overweight/obesity has been suggested as a risk factor for asthma development, and prospective studies have confirmed that high body weight precedes asthma symptoms. However, the nature of the association between overweight/obese status and asthma remains unclear. Animal models of obesity-related asthma are very useful for understanding disease pathophysiology. Although C57/B6J mice are the most widely used animal model for researching obesity-related asthma, gender differences are not always taken into consideration. Therefore, to explore the effect of gender on the development of obesity-related asthma, both female and male C57/B6J mice were used in this study. The mice were fed with a high-fat diet or a low-fat diet as control. Body weight, body length, liver weight, and Lee’s Index were used to evaluate obesity status, and lung histology, lung inflammatory cells infiltration, and inflammatory cytokines in bronchoalveolar lavage fluid (BALF) were examined for asthma evaluation. We found that the mean body weight of male mice on a high-fat diet gradually increased and was significantly higher than control male mice on a low-fat diet ( P < 0.01), while no significant differences were found between female mice at the end of 12 weeks of feeding. Furthermore, the obese asthma group female and male mice exhibited significantly high inflammatory cells infiltration than normal weight or obese female and male mice ( P < 0.01). However, the obese asthma group presented higher Neu infiltration, Th1 cytokine, and interferon gamma (IFNγ) concentrations in BALF than the asthma group in both the genders ( P < 0.01). In conclusion, both female and male mice are suitable for the obesity-related asthma model, although male mice might be more stable. Besides, obesity-related asthma is not Th2 type asthma.


2008 ◽  
Vol 15 (04) ◽  
pp. 500-507
Author(s):  
MUHAMMAD ANWAR BURIRO ◽  
MUHAMMAD TAYYAB

Objective: To determine the effects of Nigella sativa and sunflower oil diet intake on serum lipid profile in albino rats. Material& Methods: Eighty four albino rats with equal number of males and females were selected for the study, they were divided into six differentgroups, Control groups1,111,V,were given low fat diet(3%),high fat diet(20%), high fat diet supplemented with bile salt (1% colic acid) andantithyroid drug (0.5% propylthiouracil). The Experimental groups were given the above diets with supplemented Nigella sativa. Low fat dietincreased all the lipid fractions significantly when given at12 and 24 weeks duration as compared to 0 week. Results: The high fat diet whengiven at different intervals decreased all lipid fractions significantly as compared to baseline level. The high fat diet with propylthiouracil andbile salt also increased all the lipid fractions and the increase was more as compared to previous groups. The supplements of Nigella sativain the groups decreased all the lipid fractions significantly as compared to the control groups except HDL-c, which was significantly increasedin all the experimental groups as compared to control groups. Conclusion: On the basis of these findings conclusions are made, that Nigellasativa has got TG,TC, and LDL-c lowering and HDL-c raising effects.3% sunflower oil low fat diet has got TG,TC,HDL-c, and LDL-c raisingeffects.20% sunflower oil high fat diet has got TG,TC,HDL-c and LDL-c lowering effects. Both Nigella sativa and sunflower oil have got lowatherogenic index (TC/HDL) and may be recommended in hyperlipidaemic patients or normal individuals.


2003 ◽  
Vol 90 (2) ◽  
pp. 329-336 ◽  
Author(s):  
Anja Schou Lindman ◽  
Hanne Müller ◽  
Ingebjørg Seljeflot ◽  
Hans Prydz ◽  
Marit Veierød ◽  
...  

Dietary fat influences plasma levels of coagulation factor VII (FVII) and serum phospholipids (PL). It is, however, unknown if the fat-mediated changes in FVII are linked to PL. The present study aimed to investigate the effects of dietary fat on fasting and postprandial levels of activated FVII (FVIIa), FVII coagulant activity (FVIIc), FVII protein (FVIIag) and choline-containing PL (PC). In a randomized single-blinded crossover-designed study a high-fat diet (HSAFA), a low-fat diet (LSAFA), both rich in saturated fatty acids, and a high-fat diet rich in unsaturated fatty acids (HUFA) were consumed for 3 weeks. Twenty-five healthy females, in which postprandial responses were studied in a subset of twelve, were included. The HSAFA diet resulted in higher levels of fasting FVIIa and PC compared with the LSAFA and the HUFA diets (all comparisonsP≤0·01). The fasting PC levels after the LSAFA diet were also higher than after the HUFA diet (P<0·001). Postprandial levels of FVIIa and PC were highest on the HSAFA diet and different from LSAFA and HUFA (all comparisonsP≤0·05). Postprandial FVIIa was higher on the HUFA compared with the LSAFA diet (P<0·03), whereas the HUFA diet resulted in lower postprandial levels of PC than the LSAFA diet (P<0·001). Significant correlations between fasting levels of PC and FVIIc were found on all diets, whereas FVIIag was correlated to PC on the HSAFA and HUFA diet. The present results indicate that dietary fat, both quality and quantity, influences fasting and postprandial levels of FVIIa and PC. Although significant associations between fasting FVII and PC levels were found, our results do not support the assumption that postprandial FVII activation is linked to serum PC.


1992 ◽  
Vol 263 (4) ◽  
pp. R785-R789 ◽  
Author(s):  
T. A. Buchanan ◽  
J. S. Fisler ◽  
S. Underberger ◽  
G. F. Sipos ◽  
G. A. Bray

To determine whether whole body insulin sensitivity differs between a rat strain that does not (S 5B/Pl) and a strain that does [Osborne-Mendel (OM)] become obese when eating a high-fat diet, we performed euglycemic clamp studies in animals from each strain during low- and high-fat feeding. Clamps were performed after 2 days ("initial clamp") and 9 days ("final clamp") on each diet. Plasma glucose and insulin levels during the final 60 min of initial and final clamps were similar in S 5B/Pl and OM rats regardless of diet. Insulin sensitivity, measured as the glucose clearance rate during the final 60 min of the clamp, averaged 35 +/- 3 ml.kg-1.min-1 in S 5B/Pl rats after 2 days on a low-fat diet. This did not change significantly during an additional 7 days on the low-fat diet. The high-fat diet was associated with a 13% reduction in insulin sensitivity after 2 days and a 30% reduction after 9 days in S 5B/Pl rats. OM rats exhibited similar patterns of insulin sensitivity during low- and high-fat diets, albeit at lower insulin sensitivity overall (P < 0.0005 vs. S 5B/Pl). Mean glucose clearance after 2 days on the low-fat diet was 27 +/- 2 mg.kg-1.min-1 and did not change significantly during seven more days of low-fat feeding. The high-fat diet was associated with a 19% reduction in glucose clearance after 2 days and a 38% reduction after 9 days in OM rats. The magnitude of reduction in insulin sensitivity during high-fat diets did not differ significantly between strains.(ABSTRACT TRUNCATED AT 250 WORDS)


2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1699-1699
Author(s):  
Yanwen Wang ◽  
Sandhya Nair ◽  
Jacques Gagnon

Abstract Objectives The present study was designed to examine the effect of herring milt dry powder (HMDP) on glucose homeostasis and related metabolic phenotypes and compare its efficacy with herring milt protein hydrolysate (HMPH) in diet-induced obese and insulin resistant mice. Methods Male C57BL/6 J mice were pretreated with a high-fat diet for 7 weeks were divided into 3 groups where one group continued on the high-fat diet and used as the obese and insulin resistant control (HFC) and the other two groups were fed a modified HFC diet where 70% of casein was replaced with an equal percentage of protein derived from HMDP or HMPH. A group of mice fed a low-fat diet all the time was used as the normal or low-fat control (LFC). Body weight was obtained weekly and food intake was recorded daily. Semi-fating (4–6 hr) blood glucose was measured every other week using a glucometer using the blood from tail vein. Oral glucose tolerance was measured twice during weeks 5 and 9, respectively, and insulin tolerance was determined during week 7 of the treatment. At the end of the experiment, serum was obtained following overnight fasting for the measurement of fasting insulin, leptin, free fatty acids and lipids as well as other glucose metabolism-related biomarkers. Results During the 9-week treatment period, mice on the high-fat diet maintained significantly higher body weight and semi-fasting blood glucose levels and exhibited impaired oral glucose tolerance and insulin resistance relative to mice on the low-fat diet. At the end of the study, the analysis of fasting blood samples revealed that mice on the high-fat diet had increases in serum insulin, leptin, free fatty acids and cholesterol levels. Mice fed the high-fat diet also showed an increase in insulin resistance index and a decrease in β-cell function index. Compared to mice on the high-fat diet, the 70% replacement of dietary casein with an equal percentage of protein derived from HMDP or HMPH reversed or markedly improved these parameters, and HMDP and HMPH showed similar effects. Conclusions The results demonstrate that replacing dietary casein with the same amount of protein derived from either HMDP or HMPH prevents and improves high-fat-diet-induced obesity and insulin resistance. Funding Sources Atlantic Canada Opportunity Agency through the Atlantic Innovation Fund grant (no. 193,594) and National Research Council of Canada – NHP program.


2020 ◽  
Vol 96 (6) ◽  
Author(s):  
Sarah L Becker ◽  
Edna Chiang ◽  
Anna Plantinga ◽  
Hannah V Carey ◽  
Garret Suen ◽  
...  

ABSTRACT Artificial sweeteners have been shown to induce glucose intolerance by altering the gut microbiota; however, little is known about the effect of stevia. Here, we investigate whether stevia supplementation induces glucose intolerance by altering the gut microbiota in mice, hypothesizing that stevia would correct high fat diet-induced glucose intolerance and alter the gut microbiota. Mice were split into four treatment groups: low fat, high fat, high fat + saccharin and high fat + stevia. After 10 weeks of treatment, mice consuming a high fat diet (60% kcal from fat) developed glucose intolerance and gained more weight than mice consuming a low fat diet. Stevia supplementation did not impact body weight or glucose intolerance. Differences in species richness and relative abundances of several phyla were observed in low fat groups compared to high fat, stevia and saccharin. We identified two operational taxonomic groups that contributed to differences in beta-diversity between the stevia and saccharin groups: Lactococcus and Akkermansia in females and Lactococcus in males. Our results demonstrate that stevia does not rescue high fat diet-induced changes in glucose tolerance or the microbiota, and that stevia results in similar alterations to the gut microbiota as saccharin when administered in concordance with a high fat diet.


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