MONOSACCHARIDE TRANSPORT BY THE SMALL INTESTINE OF LEAN AND GENETICALLY OBESE (<i>ob/ob</i>) MICE

Morton, Ann P.; Hanson, Peter J.

doi:10.1113/expphysiol.1984.sp002772

Cited by 18 publications

(14 citation statements)

References 14 publications

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“…In order to confirm this hypothesis, it will be interesting to further study and compare GLUT4 subcellular localization in the OB of the two genotypes of Zucker rats. Concerning SGLT1, the up-regulation observed in the OB of fa/fa rats is consistent with previous studies performed on peripheral tissues in obese, hyperinsulinemic and diabetic rodent models as well in human (Morton and Hanson, 1984; Ferraris and Vinnakota, 1995; Dyer et al, 2002; Osswald et al, 2005; Tabatabai et al, 2009). In central nervous system, during pathological conditions such as ischemia or epileptic seizure which induce an over-consumption of glucose (Poppe et al, 1997; Elfeber et al, 2004) SGLT1 was up-regulated (Yu et al, 2010, 2013).…”

Section: Discussionsupporting

confidence: 90%

Modulation of olfactory sensitivity and glucose-sensing by the feeding state in obese Zucker rats

Aimé

Palouzier-Paulignan²,

Salem³

et al. 2014

Front. Behav. Neurosci.

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The Zucker fa/fa rat has been widely used as an animal model to study obesity, since it recapitulates most of its behavioral and metabolic dysfunctions, such as hyperphagia, hyperglycemia and insulin resistance. Although it is well established that olfaction is under nutritional and hormonal influences, little is known about the impact of metabolic dysfunctions on olfactory performances and glucose-sensing in the olfactory system of the obese Zucker rat. In the present study, using a behavioral paradigm based on a conditioned olfactory aversion, we have shown that both obese and lean Zucker rats have a better olfactory sensitivity when they are fasted than when they are satiated. Interestingly, the obese Zucker rats displayed a higher olfactory sensitivity than their lean controls. By investigating the molecular mechanisms involved in glucose-sensing in the olfactory system, we demonstrated that sodium-coupled glucose transporters 1 (SGLT1) and insulin dependent glucose transporters 4 (GLUT4) are both expressed in the olfactory bulb (OB). By comparing the expression of GLUT4 and SGLT1 in OB of obese and lean Zucker rats, we found that only SGLT1 is regulated in genotype-dependent manner. Next, we used glucose oxidase biosensors to simultaneously measure in vivo the extracellular fluid glucose concentrations ([Gluc]ECF) in the OB and the cortex. Under metabolic steady state, we have determined that the OB contained twice the amount of glucose found in the cortex. In both regions, the [Gluc]ECF was 2 fold higher in obese rats compared to their lean controls. Under induced dynamic glycemia conditions, insulin injection produced a greater decrease of [Gluc]ECF in the OB than in the cortex. Glucose injection did not affect OB [Gluc]ECF in Zucker fa/fa rats. In conclusion, these results emphasize the importance of glucose for the OB network function and provide strong arguments towards establishing the OB glucose-sensing as a key factor for sensory olfactory processing.

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Section: Discussionsupporting

confidence: 90%

Modulation of olfactory sensitivity and glucose-sensing by the feeding state in obese Zucker rats

Aimé

Palouzier-Paulignan²,

Salem³

et al. 2014

Front. Behav. Neurosci.

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“…Ear ly experiment s by Morton and Hans on [22] examining intestinal transport in leptin-deficient (Lep ob ) obese mice showed an increased total capacity of obese mice to transport glucose compared with lean mice. The influx of glucose per centimeter in both jejunum and ileum was greater in obese mice compared with lean controls.…”

Section: Discussionmentioning

confidence: 98%

Altered small intestinal absorptive enzyme activities in leptin-deficient obese mice: influence of bowel resection

Kiely

Noh

Svatek

et al. 2006

Journal of Pediatric Surgery

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“…We propose that BSA, a constituent protein within WPI, provides some of the bioactivity to WPI because our previous work showed that BSA reduced adiposity and plasma leptin and increased cumulative energy intake in obese mice (29), and the data presented here from that study extended the link to include the growth of the intestine. The signaling mechanism may involve leptin given that leptin-deficient (ob/ob) mice show increased intestinal weight (31).…”

Section: Discussionmentioning

confidence: 99%

Whey protein effects on energy balance link the intestinal mechanisms of energy absorption with adiposity and hypothalamic neuropeptide gene expression

Nilaweera

Cabrera‐Rubio

Speakman

et al. 2017

American Journal of Physiology-Endocrinology and Metabolism

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.2016.-We tested the hypothesis that dietary whey protein isolate (WPI) affects the intestinal mechanisms related to energy absorption and that the resulting energy deficit is compensated by changes in energy balance to support growth. C57BL/6 mice were provided a diet enriched with WPI with varied sucrose content, and the impact on energy balance-related parameters was investigated. As part of a high-sucrose diet, WPI reduced the hypothalamic expression of pro-opiomelanocortin gene expression and increased energy intake. The energy expenditure was unaffected, but epididymal weight was reduced, indicating an energy loss. Notably, there was a reduction in the ileum gene expression for amino acid transporter SLC6a19, glucose transporter 2, and fatty acid transporter 4. The composition of the gut microbiota also changed, where Firmicutes were reduced. The above changes indicated reduced energy absorption through the intestine. We propose that this mobilized energy in the adipose tissue and caused hypothalamic changes that increased energy intake, acting to counteract the energy deficit arising in the intestine. Lowering the sucrose content in the WPI diet increased energy expenditure. This further reduced epididymal weight and plasma leptin, whereupon hypothalamic ghrelin gene expression and the intestinal weight were both increased. These data suggest that when the intestine-adiposehypothalamic pathway is subjected to an additional energy loss (now in the adipose tissue), compensatory changes attempt to assimilate more energy. Notably, WPI and sucrose content interact to enable the component mechanisms of this pathway. whey proteins; gut microbiota MAMMALS ACHIEVE energy homeostasis by matching energy supply (from food consumed) with the summed energy demand of body tissues. This is achieved in part by sensing nutrient (energy) availability in the intestinal lumen, where their transport through a carrier-mediated mechanism in the circulatory system causes subsequent changes in the hypothalamic-and adipose-related mechanisms regulating energy balance (16,35,41). A growing body of evidence suggests that the gut microbiota also play important roles in energy balance regulation by influencing the related intestinal and hypothalamic cellular activities (10, 32) and by harvesting energy from ingested food and then providing it for host metabolism, including storage in the adipose tissue (3). Thus, in theory, manipulation of the gut microbiota, along with the intestinal nutrient-sensing and transport-related genes, has the potential to change the intestinal, hypothalamic, and adipose control of energy balance and body weight dynamics.Whey proteins, including bovine serum albumin (BSA) and lactoferrin, are constituents of milk (19), with the bovine form having been part of the human diet since at least the Bronze Age (51). Because these proteins are now increasingly being used in infant formula, and in food products to improve muscle mass in athletes and the elderly (18), there is a need to understand the impact of their ...

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MONOSACCHARIDE TRANSPORT BY THE SMALL INTESTINE OF LEAN AND GENETICALLY OBESE (ob/ob) MICE

Cited by 18 publications

References 14 publications

Modulation of olfactory sensitivity and glucose-sensing by the feeding state in obese Zucker rats

Modulation of olfactory sensitivity and glucose-sensing by the feeding state in obese Zucker rats

Altered small intestinal absorptive enzyme activities in leptin-deficient obese mice: influence of bowel resection

Whey protein effects on energy balance link the intestinal mechanisms of energy absorption with adiposity and hypothalamic neuropeptide gene expression

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