Ontogenetic development of monosaccharide and amino acid transporters in rabbit intestine

1990 ◽  
Vol 259 (4) ◽  
pp. G544-G555 ◽  
Author(s):  
R. K. Buddington ◽  
J. M. Diamond
Keyword(s):  
Amino Acids ◽  
Small Intestine ◽  
Metabolic Rate ◽  
Direct Proportion ◽  
Natural Diet ◽  
Sugar Absorption ◽  
Age Related ◽  
Rabbit Intestine ◽  
Small Intestinal ◽  
Rabbit Milk

We measured brush-border uptakes of seven sugars and amino acids by rabbit intestine as a function of age from the day of birth to adulthood. Gut dimensions, especially those of the colon and cecum, increase more rapidly with body weight than would be true if rabbits maintained identical proportions as they grew. However, nominal small intestinal area increases in approximately direct proportion to the animal's basal metabolic rate. For all solutes except fructose, uptake per milligram of intestinal tissue is maximal at or near birth and declines to a level 2.5-5 times lower in the adult. Because of small intestinal growth, though, the total uptake capacity of the whole length of the small intestine increases in approximately direct proportion to metabolic rate. Fructose uptake per milligram is unique in increasing steeply at the time of weaning, correlated with the post-weaning first appearance of fructose in the natural diet. Age-related changes in uptake ratios among aldohexoses or amino acids suggest developmental sequences of related transporters. Correlated with the very high protein content of rabbit milk, the proline-to-glucose uptake ratio is higher in suckling rabbits than in other sucking mammals. Remarkably, the ratio for adult rabbits is higher than in other monogastric herbivores and is instead similar to values for carnivores. In explanation, although the transport capacity of the small intestine appears to account for proline absorption in rabbits of all ages and for sugar absorption in suckling rabbits, the hindgut may be a major site of carbohydrate digestion in adult rabbits.

scholarly journals Age-related histochemical investigations of small intestinal goblet cells in bronze turkeys (Meleagris gallopavo gallopavo)

2021 ◽  
Vol 24 (2) ◽  
pp. 176-183
Author(s):  
D. Yovchev ◽  
G. Penchev
Keyword(s):  
Small Intestine ◽  
Age Groups ◽  
Negative Relationship ◽  
Meleagris Gallopavo ◽  
Cell Types ◽  
Goblet Cells ◽  
Age Related ◽  
Pas Staining ◽  
Small Intestinal ◽  
Acid Mucins

The aim of the study was to investigate the goblet cell types and their density in the small intestine of bronze turkey (Meleagris meleagris gallopovo), by means of Alcian blue-PAS staining. Sixty birds from 10 age groups were used. In the duodenum and jejunum, goblet cells produced acid, neutral and mixed mucins, while in the jejunum - acid mucins. A negative relationship was observed between cell density and either duodenum or jejunum lengths; such a correlation was not established in the ileum.

scholarly journals The small bowel microbiome changes significantly with age and aspects of the ageing process

2022 ◽  
Vol 9 (1) ◽  
pp. 21-23
Author(s):  
Gabriela Leite ◽  
Mark Pimentel ◽  
Gillian M. Barlow ◽  
Ruchi Mathur
Keyword(s):  
Small Intestine ◽  
Small Bowel ◽  
Intestinal Microbiome ◽  
Ageing Process ◽  
Age Related ◽  
Human Ageing ◽  
Stool Samples ◽  
Older Subjects ◽  
Small Intestinal ◽  
Host Metabolism

Gut microbiome changes have been associated with human ageing and implicated in age-related diseases including Alzheimer’s disease and Parkinson’s disease. However, studies to date have used stool samples, which do not represent the entire gut. Although more challenging to access, the small intestine plays critical roles in host metabolism and immune function. In this paper (Leite et al. (2021), Cell Reports, doi: 10.1016/j.celrep.2021.109765), we demonstrate significant differences in the small intestinal microbiome in older subjects, using duodenal aspirates from 251 subjects aged 18-80 years. Differences included significantly decreased microbial diversity in older subjects, driven by increased relative abundance of phylum Proteobacteria, particularly family Enterobacteriaceae and coliform genera Escherichia and Klebsiella. Moreover, while this decreased diversity was associated with the ‘ageing process’ (comprising chronologic age, number of medications, and number of concomitant diseases), changes in certain taxa were found to be associated with number of medications alone (Klebsiella), number of diseases alone (Clostridium, Bilophila), or chronologic age alone (Escherichia, Lactobacillus, Enterococcus). Lastly, many taxa associated with increasing chronologic age were anaerobes. These changes may contribute to changes in human health that occur during the ageing process.

Comparison and evaluation of protein evaluation systems currently in use in europe

1993 ◽  
Vol 1993 ◽  
pp. 6-6
Author(s):  
W.M. van Straalen ◽  
C. Salaün
Keyword(s):  
Amino Acids ◽  
Small Intestine ◽  
Amino Acid ◽  
Acid Content ◽  
Amino Acid Content ◽  
Evaluation Systems ◽  
Rumen Degradation ◽  
Small Intestinal ◽  
Feed Protein ◽  
True Protein

In modern protein evaluation systems the protein unit (PU) of a feedstuff and the requirement of PU is expressed as true protein assumed to be absorbed from the small intestine. Total PU supply originates from feed protein escaping rumen degradation and from microbial protein synthesised in the rumen. Escape feed PU is calculated from crude protein (CP) multiplied by the escape CP fraction, amino acid content of escape CP and small intestinal digestibility of escape amino acids. Microbial PU is calculated from the energy source for microbial growth multiplied by the efficiency by which this energy is used for microbial CP synthesis, amino acid content of microbial CP and the digestibility in the small intestine of microbial amino acids.

What transport adaptations enable mammals to absorb sugars and amino acids faster than reptiles?

1985 ◽  
Vol 249 (2) ◽  
pp. G271-G283 ◽  
Author(s):  
W. H. Karasov ◽  
D. H. Solberg ◽  
J. M. Diamond
Keyword(s):  
Small Intestine ◽  
Transport Activity ◽  
Uptake Capacity ◽  
Passive Permeability ◽  
Natural Diet ◽  
Reptile Species ◽  
Small Intestinal ◽  
Lower Temperature ◽  
Similar Body ◽  
Mammalian Intestine

What digestive adaptations enable mammals to process much more food in much less time with equal or higher digestive efficiency than reptiles and thus to sustain much higher metabolic rates? To answer this question, we measured glucose and proline uptake in small intestinal sleeves of three mammal and three reptile species of similar body size and natural diet. All species exhibit saturable, stereospecific uptake of D-glucose and Na+-dependent L-proline uptake. Passive permeability to glucose is high in hamsters and low in the other species. Uptake increases with temperature up to a maximum around 45–50 degrees C. This temperature dependence may help explain why reptiles bask after meals and why their digestion is impaired if basking is prevented. The total uptake capacity of the small intestine for glucose and proline is seven times higher in mammals than similar-sized reptiles, mainly because the area of mammalian intestine is 4–5.5 times greater. Minor reasons for the higher uptake capacity of mammals are that the transport activity of mammal intestine normalized to quantity of tissue is up to twofold higher and that reptile intestine operates at a lower temperature at night. Vmax for glucose transport varies 10-fold among species, but apparent differences in Km values may be unstirred-layer artifacts. Carrier-mediated uptake of glucose and proline is measurable in the colon of at least three species, but the uptake capacity of the colon is less than 10% of that of the small intestine. An appendix presents a method for measuring the microscopic area of intestines with ridges rather than villi, applies this method to desert iguana intestine, and measures area amplification due to villi in wood rat intestine.

scholarly journals Association of Human Plasma Metabolomics with Delayed Dark Adaptation in Age-Related Macular Degeneration

Metabolites ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 183
Author(s):  
Kevin M Mendez ◽  
Janice Kim ◽  
Inês Laíns ◽  
Archana Nigalye ◽  
Raviv Katz ◽  
...  
Keyword(s):  
Amino Acids ◽  
Fatty Acid ◽  
Macular Degeneration ◽  
Dark Adaptation ◽  
Ultra Performance Liquid Chromatography ◽  
Cross Sectional Study ◽  
Age Related Macular Degeneration ◽  
Cross Sectional ◽  
Age Related ◽  
Vitreoretinal Disease

The purpose of this study was to analyze the association between plasma metabolite levels and dark adaptation (DA) in age-related macular degeneration (AMD). This was a cross-sectional study including patients with AMD (early, intermediate, and late) and control subjects older than 50 years without any vitreoretinal disease. Fasting blood samples were collected and used for metabolomic profiling with ultra-performance liquid chromatography–mass spectrometry (LC-MS). Patients were also tested with the AdaptDx (MacuLogix, Middletown, PA, USA) DA extended protocol (20 min). Two measures of dark adaptation were calculated and used: rod-intercept time (RIT) and area under the dark adaptation curve (AUDAC). Associations between dark adaption and metabolite levels were tested using multilevel mixed-effects linear modelling, adjusting for age, gender, body mass index (BMI), smoking, race, AMD stage, and Age-Related Eye Disease Study (AREDS) formulation supplementation. We included a total of 71 subjects: 53 with AMD (13 early AMD, 31 intermediate AMD, and 9 late AMD) and 18 controls. Our results revealed that fatty acid-related lipids and amino acids related to glutamate and leucine, isoleucine and valine metabolism were associated with RIT (p < 0.01). Similar results were found when AUDAC was used as the outcome. Fatty acid-related lipids and amino acids are associated with DA, thus suggesting that oxidative stress and mitochondrial dysfunction likely play a role in AMD and visual impairment in this condition.

scholarly journals Formaldehyde and De/Methylation in Age-Related Cognitive Impairment

Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 913
Author(s):  
Ting Li ◽  
Yan Wei ◽  
Meihua Qu ◽  
Lixian Mou ◽  
Junye Miao ◽  
...  
Keyword(s):  
Amino Acids ◽  
Cell Proliferation ◽  
Cognitive Impairment ◽  
Metabolic Pathways ◽  
Memory Formation ◽  
Epigenetic Alterations ◽  
Diagnostic Biomarker ◽  
Reactive Substance ◽  
Age Related ◽  
Novel Therapeutic

Formaldehyde (FA) is a highly reactive substance that is ubiquitous in the environment and is usually considered as a pollutant. In the human body, FA is a product of various metabolic pathways and participates in one-carbon cycle, which provides carbon for the synthesis and modification of bio-compounds, such as DNA, RNA, and amino acids. Endogenous FA plays a role in epigenetic regulation, especially in the methylation and demethylation of DNA, histones, and RNA. Recently, epigenetic alterations associated with FA dysmetabolism have been considered as one of the important features in age-related cognitive impairment (ARCI), suggesting the potential of using FA as a diagnostic biomarker of ARCI. Notably, FA plays multifaceted roles, and, at certain concentrations, it promotes cell proliferation, enhances memory formation, and elongates life span, effects that could also be involved in the aetiology of ARCI. Further investigation of and the regulation of the epigenetics landscape may provide new insights about the aetiology of ARCI and provide novel therapeutic targets.

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