Feeding rats a high fat/carbohydrate ratio diet reduces jejunal S/I activity ratio and unsialylated galactose on glycosylated chain of S–I complex

Mochizuki, Kazuki; Igawa-Tada, Makiko; Takase, Sachiko; Goda, Toshinao

doi:10.1016/j.lfs.2010.02.011

Cited by 8 publications

(2 citation statements)

References 40 publications

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“…In addition, sucrase-isomaltase has N-and O-linked glycosylated chains, and glycosylation inhibition reduces the transfer of the protein to the apical membrane of the enterocyte (references in Reference 110), suggesting the importance of sucrase-isomaltase glycosylation for expressing the enzyme complex at the brush-border membrane. In rats fed a high fat-to-carbohydrate-ratio diet for 14 days, Mochizuki et al (110) observed that the reduced ratio of jejunal sucrase activity to isomaltase activity was associated with the reduction of unsialylated galactose from the glycosylated chain of sucrase-isomaltase, perhaps limiting the mobilization of the enzyme complex to the apical cell membrane and reducing the complex's activity. Whether the effect of lipids on carbohydrases has a biological meaning or is just a side effect is unknown and begs for further clarification.…”

Section: Unexpected Patternsmentioning

confidence: 99%

Ecological Physiology of Diet and Digestive Systems

Karasov

Rio

Caviedes‐Vidal

2011

Annu. Rev. Physiol.

294

246

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The morphological and functional design of gastrointestinal tracts of many vertebrates and invertebrates can be explained largely by the interaction between diet chemical constituents and principles of economic design, both of which are embodied in chemical reactor models of gut function. Natural selection seems to have led to the expression of digestive features that approximately match digestive capacities with dietary loads while exhibiting relatively modest excess. Mechanisms explaining differences in hydrolase activity between populations and species include gene copy number variations and single-nucleotide polymorphisms. In many animals, both transcriptional adjustment and posttranscriptional adjustment mediate phenotypic flexibility in the expression of intestinal hydrolases and transporters in response to dietary signals. Digestive performance of animals depends also on their gastrointestinal microbiome. The microbiome seems to be characterized by large beta diversity among hosts and by a common core metagenome and seems to differ flexibly among animals with different diets.

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Section: Unexpected Patternsmentioning

confidence: 99%

Ecological Physiology of Diet and Digestive Systems

Karasov

Rio

Caviedes‐Vidal

2011

Annu. Rev. Physiol.

294

246

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“…Because changes in mass-specific activities of carbohydrases and aminopeptidase-N in our experiment differed in both direction and magnitude (Fig.3), we hypothesize that observed diet effects were probably mediated by site-specific changes in the rate of synthesis or degradation of carbohydrases. Studies in rodents revealed several genetic and molecular mechanisms that can be responsible for such changes (Takase and Goda, 1990;Shinohara et al, 1993;Kishi et al, 1999;Goda, 2000;Honma et al, 2007;Tanaka et al, 2008;Mochizuki et al, 2010a;Mochizuki et al, 2010b). We cannot pinpoint the mechanisms that were responsible for dietary modulation of intestinal carbohydrase activities observed in our experiment.…”

Section: Molecular Basis For Observed Dietary Modification Of Intestimentioning

confidence: 69%

Activity of intestinal carbohydrases responds to multiple dietary signals in nestling House sparrows

Brzęk

Kohl

Caviedes‐Vidal

et al. 2013

Journal of Experimental Biology

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SUMMARYThe 'adaptive modulation hypothesis' predicts that activity of digestive enzymes should match the amount of their substrates in diet. Interestingly, many passerine birds do not adjust the activity of intestinal carbohydrases to dietary carbohydrate content. It is difficult to assess the generality of this rule, because in some studies passerines fed on low-carbohydrate and high-lipid diet showed reduced activity of intestinal carbohydrases. However, as carbohydrase activity may be inhibited by high dietary lipid content, it is unclear whether observed effects reflected lack of induction by the low carbohydrate levels or suppression by the high lipid levels. Here, we isolated the specific effects of dietary carbohydrate and lipid on carbohydrases. We hand-fed house sparrow nestlings on diets with 25% starch and 8% lipid (diet HS), no starch and 20% lipid (HL), or 25% starch and 20% lipid (HSL). Our results show that activity of intestinal carbohydrases is simultaneously induced by dietary carbohydrates and decreased by dietary lipid, although the latter effect seems stronger. Activities of maltase and sucrase summed over the total intestine decreased in the order HS>HSL>HL. We observed a complex interaction between diet composition and intestinal position for mass-specific activity of these enzymes, suggesting site-specific responses to changes in digesta composition along the intestines caused by digestion and absorption. We re-interpret results of earlier studies and conclude that there is no unequivocal example of adaptive modulation of intestinal carbohydrases by dietary carbohydrate in adult passerine birds, whereas the present experiment confirms that nestlings of at least some species possess such capacity.

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