Tests of the adaptive modulation hypothesis for dietary control of intestinal nutrient transport

1992 ◽  
Vol 263 (3) ◽  
pp. R496-R502 ◽  
Author(s):  
W. H. Karasov
Keyword(s):  
Adaptive Modulation ◽  
Pantothenic Acid ◽  
Dietary Factors ◽  
Water Soluble ◽  
Dietary Control ◽  
Carbohydrate Diet ◽  
Water Soluble Vitamin ◽  
Uptake Rates ◽  
Low Carbohydrate ◽  
Intestinal Transporter

According to the adaptive modulation hypothesis, an intestinal transporter should be repressed when its biosynthetic and other costs (of maintenance) exceed the benefits it provides. This leads to two contrasting predictions: transport of a sugar or amino acid worth calories should tend to be increased by its substrate, and transport of a vitamin should be modulated downwards by its substrate and upmodulated in deficiency. In a test of the first prediction, omnivorous desert iguanas eating alfalfa pellets (a high-carbohydrate diet) were compared with desert iguanas eating mealworms (a low-carbohydrate, higher-protein diet). In accord with the prediction, intact intestinal sleeves from the former group had higher rates of carrier-mediated D-glucose uptake/centimeter across the brush border than sleeves from the latter group. But in contrast to the first prediction, mealworm eaters had lower (not higher) proline uptake rates, and the ratio of glucose/proline uptake in the two groups did not differ. I review similar tests in 12 other species and show that overall the hypothesis has been quite robust with regard to the first prediction. Cases in which the hypothesis is rejected may reflect complications associated with changes in other dietary factors or phylogenetic constraints. In a test of the second prediction, uptake of the water-soluble vitamin choline was not increased in choline-deficient chicks, nor was it decreased in adults that have no dietary requirement for choline. I review similar tests for four other vitamins and five essential minerals. Dietary control of transport of the minerals and two of the vitamins seems to be in accord with the hypothesis. But transport rate for three vitamins (choline, pantothenic acid, ascorbic acid) seems not to be increased in deficiency. The best explanation seems to be that vitamin transport is modulated only if it is primarily by a carrier-mediated pathway.

scholarly journals Conditional knockout of the Slc5a6 gene in mouse intestine impairs biotin absorption

2013 ◽  
Vol 304 (1) ◽  
pp. G64-G71 ◽  
Author(s):  
Abhisek Ghosal ◽  
Nils Lambrecht ◽  
Sandeep B. Subramanya ◽  
Rubina Kapadia ◽  
Hamid M. Said
Keyword(s):  
Pantothenic Acid ◽  
Microscopic Analysis ◽  
Water Soluble ◽  
Conditional Knockout ◽  
Relative Contribution ◽  
Transport Studies ◽  
Water Soluble Vitamin ◽  
Active Inflammation

The Slc5a6 gene expresses a plasma membrane protein involved in the transport of the water-soluble vitamin biotin; the transporter is commonly referred to as the sodium-dependent multivitamin transporter (SMVT) because it also transports pantothenic acid and lipoic acid. The relative contribution of the SMVT system toward carrier-mediated biotin uptake in the native intestine in vivo has not been established. We used a Cre/lox technology to generate an intestine-specific (conditional) SMVT knockout (KO) mouse model to address this issue. The KO mice exhibited absence of expression of SMVT in the intestine compared with sex-matched littermates as well as the expected normal SMVT expression in other tissues. About two-thirds of the KO mice died prematurely between the age of 6 and 10 wk. Growth retardation, decreased bone density, decreased bone length, and decreased biotin status were observed in the KO mice. Microscopic analysis showed histological abnormalities in the small bowel (shortened villi, dysplasia) and cecum (chronic active inflammation, dysplasia) of the KO mice. In vivo (and in vitro) transport studies showed complete inhibition in carrier-mediated biotin uptake in the intestine of the KO mice compared with their control littermates. These studies provide the first in vivo confirmation in native intestine that SMVT is solely responsible for intestinal biotin uptake. These studies also provide evidence for a casual association between SMVT function and normal intestinal health.

scholarly journals Effects of Excess Pantothenic Acid Administration on the Other Water-Soluble Vitamin Metabolisms in Rats

2005 ◽  
Vol 51 (6) ◽  
pp. 385-391 ◽  
Author(s):  
Katsumi SHIBATA ◽  
Chisato TAKAHASHI ◽  
Tsutomu FUKUWATARI ◽  
Ryuzo SASAKI
Keyword(s):  
Pantothenic Acid ◽  
Water Soluble ◽  
The Other ◽  
Water Soluble Vitamin ◽  
Acid Administration

The Role of Nicotinic Acid (Niacin) in Mental Health and Disease

1955 ◽  
Vol 101 (422) ◽  
pp. 85-109 ◽  
Author(s):  
Ian Gregory
Keyword(s):  
General Term ◽  
Dietary Factors ◽  
Water Soluble ◽  
Crystalline Substance ◽  
Vitamin B ◽  
Polished Rice ◽  
Water Soluble Vitamin ◽  
Erroneous Belief ◽  
Health And Disease

Shortly before the end of the last century, Eijkman observed that fowl receiving a diet of polished rice developed a disease which he believed to be of the same nature as human beri-beri. It was subsequently shown that this condition in fowl (polyneuritis gallinarum), and beri-beri in man, could both be cured by the addition to the diet of rice polishings or an extract prepared from them. In 1911, Funk obtained from rice polishings a crystalline substance capable of preventing or curing beri-beri, which he named “vitamine” in view of its evident importance to life, and in the erroneous belief that it had the chemical structure of an amine. Four years later, McCollum and Davis demonstrated that at least two such dietary factors were necessary for growth in rats—“fat-soluble A” and “water-soluble B”. Before long it was recognized that the latter factor had the properties of the antineuritic “vitamine“, and a number of similar organic compounds were discovered, which were essential constituents of the diet in minute quantities, and for which the general term “vitamin”, was agreed upon. For several years it was assumed that water-soluble vitamin B (contained in yeast, rice polish, liver, etc.) was a single entity, but in 1919 Mitchell noted that certain vegetables rich in the antineuritic principle had little power to promote growth, and in 1926 two fractions were distinguished, each essential for growth—thermolabile vitaminB1, containing the antineuritic principle (thiamin), and thermostable vitamin B2.

scholarly journals Twenty-four-hour urinary water-soluble vitamin levels correlate with their intakes in free-living Japanese schoolchildren

2010 ◽  
Vol 14 (2) ◽  
pp. 327-333 ◽  
Author(s):  
Tomiko Tsuji ◽  
Tsutomu Fukuwatari ◽  
Satoshi Sasaki ◽  
Katsumi Shibata
Keyword(s):  
Elementary School ◽  
Pantothenic Acid ◽  
Water Soluble ◽  
Vitamin B ◽  
Food Record ◽  
Free Living ◽  
Water Soluble Vitamin ◽  
Potential Biomarker ◽  
Urinary Levels ◽  
Weighed Food Record

AbstractObjectiveTo examine the association between 24 h urinary water-soluble vitamin levels and their intakes in free-living Japanese schoolchildren.DesignAll foods consumed for four consecutive days were recorded accurately by a weighed food record. A single 24 h urine sample was collected on the fourth day, and the urinary levels of water-soluble vitamins were measured.SettingAn elementary school in Inazawa City, Japan.SubjectsA total of 114 healthy, free-living, Japanese elementary-school children aged 10–12 years.ResultsThe urinary level of each water-soluble vitamin was correlated positively to its mean intake in the past 2–4 d (vitamin B1: r = 0·42, P < 0·001; vitamin B2: r = 0·43, P < 0·001; vitamin B6: r = 0·49, P < 0·001; niacin: r = 0·32, P < 0·001; niacin equivalents: r = 0·32, P < 0·001; pantothenic acid: r = 0·32, P < 0·001; folic acid: r = 0·27, P < 0·01; vitamin C: r = 0·39, P < 0.001), except for vitamin B12 (r = 0·10, P = NS). Estimated mean intakes of water-soluble vitamins calculated using urinary levels and recovery rates were 97–102 % of their 3 d mean intake, except for vitamin B12 (79 %).ConclusionsThe results show that urinary levels of water-soluble vitamins, except for vitamin B12, reflected their recent intakes in free-living Japanese schoolchildren and could be used as a potential biomarker to estimate mean vitamin intake.

Vitamin Profile of Some Standardized Nigerian Composite Dishes

2010 ◽  
Vol 80 (6) ◽  
pp. 378-385 ◽  
Author(s):  
Onabanjo ◽  
Aderibigbe ◽  
Akinyemi ◽  
Adetogun
Keyword(s):  
Vitamin D ◽  
Vitamin C ◽  
Pantothenic Acid ◽  
Food Composition ◽  
Water Soluble ◽  
Total Vitamin ◽  
Water Soluble Vitamin ◽  
Food Composition Data ◽  
Fat Soluble Vitamins ◽  
Representative Samples

The purpose of the study was to determine the vitamin content of twenty standardized dishes commonly consumed in Nigeria. Representative samples of twenty Nigerian dishes were analyzed for fat-soluble (vitamins A, D, E, and K) and water-soluble (vitamin C and B- complexes) vitamins. The foods analyzed included those based on cereals, starchy tubers and roots, legumes, and vegetables. The analysis was carried out using spectrophotometry. The results revealed the following concentrations (mg/100 g): vitamin C , undetectable to 2.692 mg/100 g; thiamine, 0.011 - 1.094 mg/100 g; riboflavin, 0.011 - 0.816 mg/100 g; pyridoxine, undetectable to 0.412 mg/100 g; niacin, 0.070 - 0.967 mg/100 g; pantothenic acid, 0.060 - 1.193 mg/100 g; biotin, undetectable to 2.092 mg/100 g; B12, 0.045 - 2.424 µg/100 g; folate, 7.822 - 101.764 µg/100 g; total vitamin A, undetectable to 121.444 µg RE/100 g; vitamin D, undetectable to 2.445 IU/100 g; vitamin E, undetectable to 2.627 IU/100 g; and vitamin K, 0.266 - 13.091 µg/100 g. The results suggest that these dishes are good sources of fat-soluble and water-soluble vitamins and will provide baseline data that will be valuable in complementing available food composition data, and in estimating dietary intake of vitamins in Nigeria.

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