Conversion of 2-Hydroxy-4-(Methylthio)butanoic Acid to L-Methionine in the Chick: A Stereospecific Pathway

Dibner, J. J.; Knight, C. D.

doi:10.1093/jn/114.9.1716

Cited by 120 publications

(93 citation statements)

References 18 publications

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“…From 08.00 to 14.00 hours, pigs were offered meals at hourly intervals, and the meal was the equivalent of one twenty-fourth of the daily intake (45 g/kg BW). Immediately after the first meal, piglets received a constant infusion of [1-13 C]methionine, suspended in water via the gastric catheter at a rate of about 0·25 ml/min to provide [1][2][3][4][5][6][7][8][9][10][11][12][13] C]methionine at 7·0 mmol/kg BW per h. After the tracer infusion was started, the piglets continued to receive hourly meals. Arterial and portal blood samples were taken at hourly intervals until 6 h of tracer infusion, and all the blood samples were immediately placed on ice.…”

Section: Infusion Protocol and Blood Collectionmentioning

confidence: 99%

Effects ofdl-2-hydroxy-4-methylthiobutyrate on the first-pass intestinal metabolism of dietary methionine and its extra-intestinal availability

et al. 2010

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The present study was conducted in a one-factorial arrangement to determine the effects of DL-2-hydroxy-4-methylthiobutyrate (DL-HMTB) on the first-pass intestinal metabolism of dietary methionine and its extra-intestinal availability. Barrows (n 6; aged 35 d; weight 8·6 kg), implanted with arterial, portal, mesenteric and gastric catheters, were fed a diet containing DL-methionine (DL-MET) or DL-HMTB once hourly and infused intramesenterically with 1 % p-aminohippurate and intragastrically with [1-13 C]methionine at 7·0 mmol/kg body weight per h. Arterial and portal blood samples were taken at hourly intervals until 6 h of tracer infusion and pigs was then killed for collection of muscle, intestine, liver and kidney samples. The net portal appearance of methionine, expressed as the fraction of ingested directly available L-methionine, was higher (P,0·05) in the DL-HMTB than in the DL-MET diet, and there was no difference (P¼ 0·26) in the fractional portal balance of [1-13 C]methionine between the diets. [1-13 C]methionine enrichment (tracer:tracee ratio; mol/100 mol amino acid) in the jejunum, arterial and portal plasma, liver, kidney and muscle was also not different (P.0·05) between the groups. Over the 6 h period after the start of feeding, the average concentration of citrulline both in the arterial and portal plasma was higher (P,0·05) in the DL-HMTB than in the DL-MET group, and arterial plasma ornithine and taurine concentration was also higher (P,0·05) in the DL-HMTB than in the DL-MET group. However, plasma urea concentration both in the arterial and portal vein was lower (P, 0·05) in the DL-HMTB than in the DL-MET group. These results suggested that the potential difference in the first-pass use of methionine by the intestine between the DL-HMTB and DL-MET diets might affect intestinal and systemic metabolism of other amino acids, which may provide new important insights into nutritional efficiency of different methionine sources.DL-2-Hydroxy-4-methylthiobutyrate: First-pass intestinal metabolism: Extra-intestinal availabilityThe small intestine is a highly differentiated and complex organ, which is not only responsible for the terminal digestion and absorption of nutrients, but also plays an important role in the synthesis, conversion and catabolism of amino acids (1) . Because the apical and basolateral membranes of each enterocyte are chemically, biochemically and physically distinct (2) , an enterocyte can selectively receive nutrients from two sources: the arterial blood across its basolateral membrane and the intestinal lumen across its brush-border membrane. Historically, it is assumed that the primary fate of essential amino acids is to protein synthesis in the target organs; however, intriguing data have demonstrated that catabolism dominates the first-pass utilisation of these amino acids by the gut (3) . Because the extensive catabolism of dietary essential amino acids by the small intestine results in a decrease in their nutritional efficiency (1,3,4) , the question whether the catabolism ...

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Section: Infusion Protocol and Blood Collectionmentioning

confidence: 99%

Effects ofdl-2-hydroxy-4-methylthiobutyrate on the first-pass intestinal metabolism of dietary methionine and its extra-intestinal availability

et al. 2010

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“…KNIGHT & DIBNER (1984) Após a absorção, a L-Met não precisa sofrer qualquer alteração para ser usada na síntese das proteínas, entretanto a D-Met e os isômeros da MHA-FA deverão sofrer alterações de tal forma que, após transformações metabólicas, resultam também em L-Met e que somente nesta forma podem ser incorporadas em qualquer proteína. DIBNER & KNIGHT (1984) observaram que, no fígado de aves bem como em outros tecidos, têm sido encontradas enzimas capazes de oxidar os dois isomêros, D e L de MHA-FA. Após a oxidação da D-Met e dos isomêros de MHA-FA, eles são transformados em L-Met por transaminação.…”

Section: Introductionunclassified

Níveis de substituição da DL-metionina pela metionina hidróxi análoga em base equimolar, em dietas para frangos de corte

et al. 2005

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Levels of substitution of Dl-methionine by methionine hidroxy analogue in basis equimolar in broilers diets RESUMO Este trabalho objetivou testar o efeito de níveis de substituição da DL-Metionina (DL-Met) por Metionina Hidróxi Análoga acido livre (MHA-FA INTRODUÇÃOOs aminoácidos são as moléculas básicas formadoras das proteínas. Com um aporte equilibrado de aminoácidos essenciais, são necessários menores quantidades de alimentos para produzir frango de corte e, conseqüentemente, uma conversão alimentar mais eficaz. Para se obter uma dieta equilibrada, formulada à base de milho e soja e que contenha todos aminoácidos essenciais, nas quantidades mínimas requeridas para o bom desempenho das aves, muitas vezes, é necessária a inclusão de aminoácidos sob a forma sintética. Atualmente, no mercado, existe disponibilidade dos aminoácidos: metionina, lisina, treonina e triptofano; a metionina é o mais limitante aminoácido essencial nas dietas de frangos de corte, Recebido para publicação 09.03.05 Aprovado em 01.06.05

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“…The chelated zinc molecule is then cleaved at the gut wall with the mineral ions being transported and the HMTBa diffusing passively into the epithelial layer. The HMTBa is converted into L-methionine via a series of enzymatic steps and is utilizable by the animal (Dibner and Knight, 1984;Dibner et al, 1987;Forster and Dominy, 2006;Yi et al, 2007;Richards et al, 2010). This enables the chelated zinc source to be more available despite the presence of antagonistic factors and as a result less supplemental zinc is required to satisfy the requirement of the animal and promote growth.…”

Section: Discussionmentioning

confidence: 99%

Availability of Dietary Zinc Sources and Effects on Performance of Pacific White Shrimp <i>Litopenaeus vannamei</i>(Boone)

Bharadwaj¹,

Patnaik²,

Browdy³

et al. 2017

International Journal of Recirculating Aquaculture

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A study was conducted to evaluate the response of Pacific white shrimp Litopenaeus vannamei to inorganic or chelated sources of dietary zinc. Two sets of diets, one supplemented with zinc from zinc sulfate (55, 80, 116, 168, 243 and 363 ppm zinc) and the other with zinc from a chelated source (methionine hydroxy analog chelate; 39, 52, 65, 78 and 104 ppm zinc) were fed to replicate groups of juvenile shrimp (N = 8; 0.4 g initial weight) for 6 wk. All experimental diets contained 1.38% phytic acid reflecting levels in typical commercial feeds. Final weight, growth rate and biomass of shrimp fed zinc sulfate supplemented diets (243 and 363 ppm total zinc) were significantly higher (p < 0.05) than that in shrimp fed the base diet. In contrast, performance of shrimp fed the chelated source of zinc was significantly higher than shrimp in the control group at much lower levels of supplementation (65 and 78 ppm total zinc). Results indicate that shrimp required 3-4 times more dietary zinc from zinc sulfate than zinc from a chelated source to promote comparable growth when fed diets containing phytic acid. The chelate tested proved to be a safe, effective and available source of zinc for the Pacific white shrimp.

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Conversion of 2-Hydroxy-4-(Methylthio)butanoic Acid to L-Methionine in the Chick: A Stereospecific Pathway

Cited by 120 publications

References 18 publications

Effects ofdl-2-hydroxy-4-methylthiobutyrate on the first-pass intestinal metabolism of dietary methionine and its extra-intestinal availability

Effects ofdl-2-hydroxy-4-methylthiobutyrate on the first-pass intestinal metabolism of dietary methionine and its extra-intestinal availability

Níveis de substituição da DL-metionina pela metionina hidróxi análoga em base equimolar, em dietas para frangos de corte

Availability of Dietary Zinc Sources and Effects on Performance of Pacific White Shrimp <i>Litopenaeus vannamei</i>(Boone)

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