Absorption of 2-hydroxy-4-methylthiobutyrate and conversion to methionine in lambs

Gerald Lobley, T J Wester, Alexander Graham Calder, D S Parker, J J Dibner, M Vázquez-Añón

Research output: Contribution to journalArticle

31 Citations (Scopus)

Abstract

Absorption and metabolism of the Met hydroxy analog 2-hydroxy-4-methylthiobutyrate (HMTBA) was examined using stable isotopes. In the first trial, Dl[1-13C]HMTBA was infused for 6 h (7.4 micromol/min) into the abomasum, and [2H3]Met was infused into the mesenteric vein, of 4 lambs prepared with vascular catheters across the splanchnic bed. Daily, lambs were offered 35 g of a mixed forage-concentrate feed/kg. Recovery of HMTBA at the portal vein was 87%, and of this, 63% bypassed the liver. In contrast, hepatic extraction of Met equaled or exceeded net absorption. Only small quantities of Met synthesized from HMTBA were exported from either the digestive tract or liver, but there was substantial and significant input from posthepatic tissues. In a second experiment, 3 of the lambs were killed following 4-h infusions of DL[1-13C]HMTBA and [2H3]Met with enrichments monitored in 15 tissues. Only kidney showed [1-13C]Met enrichment higher than plasma, which suggests that it must be a primary source of plasma Met derived from HMTBA. Based on comparison of plasma and intracellular [1-13C]:[2H3]Met enrichments, all tissues synthesized Met from HMTBA but to significantly different extents. The lowest values were for muscle, skin, brain, and lung; intermediate conversions occurred in rumen, omasum, abomasum, duodenum, jejunum, ileum, and cecum; and the greatest synthesis, equivalent to 22 to 24% of Met entry into cells, was observed for liver and kidney. Therefore, although liver and kidney both converted HMTBA to Met, it was retained by the former and exported by the latter. Under these experimental conditions, synthesis of Met from HMTBA completely eliminated use of dietary Met.
Original languageEnglish
Pages (from-to)1072-1080
Number of pages9
JournalJournal of Dairy Science
Volume89
Issue number3
DOIs
Publication statusPublished - 1 Mar 2006

Fingerprint

Methionine
methionine
lambs
liver
abomasum
kidneys
Liver
Abomasum
omasum
portal vein
synthesis
feed concentrates
Kidney
jejunum
duodenum
blood vessels
skin (animal)
catheters
ileum
digestive tract

Keywords

  • Abomasum
  • Absorption
  • Animals
  • Carbon Isotopes
  • Catheterization
  • Diet
  • Isotope Labeling
  • Kidney
  • Liver
  • Mesenteric Veins
  • Methionine
  • Organ Specificity
  • Portal Vein
  • Sheep

Cite this

Lobley, G., Wester, T. J., Calder, A. G., Parker, D. S., Dibner, J. J., & Vázquez-Añón, M. (2006). Absorption of 2-hydroxy-4-methylthiobutyrate and conversion to methionine in lambs. Journal of Dairy Science, 89(3), 1072-1080. https://doi.org/10.3168/jds.S0022-0302(06)72175-0

Absorption of 2-hydroxy-4-methylthiobutyrate and conversion to methionine in lambs. / Lobley, Gerald; Wester, T J; Calder, Alexander Graham; Parker, D S; Dibner, J J; Vázquez-Añón, M.

In: Journal of Dairy Science, Vol. 89, No. 3, 01.03.2006, p. 1072-1080.

Research output: Contribution to journalArticle

Lobley, G, Wester, TJ, Calder, AG, Parker, DS, Dibner, JJ & Vázquez-Añón, M 2006, 'Absorption of 2-hydroxy-4-methylthiobutyrate and conversion to methionine in lambs', Journal of Dairy Science, vol. 89, no. 3, pp. 1072-1080. https://doi.org/10.3168/jds.S0022-0302(06)72175-0
Lobley, Gerald ; Wester, T J ; Calder, Alexander Graham ; Parker, D S ; Dibner, J J ; Vázquez-Añón, M. / Absorption of 2-hydroxy-4-methylthiobutyrate and conversion to methionine in lambs. In: Journal of Dairy Science. 2006 ; Vol. 89, No. 3. pp. 1072-1080.
@article{f5f8bdb91e0342c2a4a19a3ebab7699f,
title = "Absorption of 2-hydroxy-4-methylthiobutyrate and conversion to methionine in lambs",
abstract = "Absorption and metabolism of the Met hydroxy analog 2-hydroxy-4-methylthiobutyrate (HMTBA) was examined using stable isotopes. In the first trial, Dl[1-13C]HMTBA was infused for 6 h (7.4 micromol/min) into the abomasum, and [2H3]Met was infused into the mesenteric vein, of 4 lambs prepared with vascular catheters across the splanchnic bed. Daily, lambs were offered 35 g of a mixed forage-concentrate feed/kg. Recovery of HMTBA at the portal vein was 87{\%}, and of this, 63{\%} bypassed the liver. In contrast, hepatic extraction of Met equaled or exceeded net absorption. Only small quantities of Met synthesized from HMTBA were exported from either the digestive tract or liver, but there was substantial and significant input from posthepatic tissues. In a second experiment, 3 of the lambs were killed following 4-h infusions of DL[1-13C]HMTBA and [2H3]Met with enrichments monitored in 15 tissues. Only kidney showed [1-13C]Met enrichment higher than plasma, which suggests that it must be a primary source of plasma Met derived from HMTBA. Based on comparison of plasma and intracellular [1-13C]:[2H3]Met enrichments, all tissues synthesized Met from HMTBA but to significantly different extents. The lowest values were for muscle, skin, brain, and lung; intermediate conversions occurred in rumen, omasum, abomasum, duodenum, jejunum, ileum, and cecum; and the greatest synthesis, equivalent to 22 to 24{\%} of Met entry into cells, was observed for liver and kidney. Therefore, although liver and kidney both converted HMTBA to Met, it was retained by the former and exported by the latter. Under these experimental conditions, synthesis of Met from HMTBA completely eliminated use of dietary Met.",
keywords = "Abomasum, Absorption, Animals, Carbon Isotopes, Catheterization, Diet, Isotope Labeling, Kidney, Liver, Mesenteric Veins, Methionine, Organ Specificity, Portal Vein, Sheep",
author = "Gerald Lobley and Wester, {T J} and Calder, {Alexander Graham} and Parker, {D S} and Dibner, {J J} and M V{\'a}zquez-A{\~n}{\'o}n",
year = "2006",
month = "3",
day = "1",
doi = "10.3168/jds.S0022-0302(06)72175-0",
language = "English",
volume = "89",
pages = "1072--1080",
journal = "Journal of Dairy Science",
issn = "0022-0302",
publisher = "Elsevier Limited",
number = "3",

}

TY - JOUR

T1 - Absorption of 2-hydroxy-4-methylthiobutyrate and conversion to methionine in lambs

AU - Lobley, Gerald

AU - Wester, T J

AU - Calder, Alexander Graham

AU - Parker, D S

AU - Dibner, J J

AU - Vázquez-Añón, M

PY - 2006/3/1

Y1 - 2006/3/1

N2 - Absorption and metabolism of the Met hydroxy analog 2-hydroxy-4-methylthiobutyrate (HMTBA) was examined using stable isotopes. In the first trial, Dl[1-13C]HMTBA was infused for 6 h (7.4 micromol/min) into the abomasum, and [2H3]Met was infused into the mesenteric vein, of 4 lambs prepared with vascular catheters across the splanchnic bed. Daily, lambs were offered 35 g of a mixed forage-concentrate feed/kg. Recovery of HMTBA at the portal vein was 87%, and of this, 63% bypassed the liver. In contrast, hepatic extraction of Met equaled or exceeded net absorption. Only small quantities of Met synthesized from HMTBA were exported from either the digestive tract or liver, but there was substantial and significant input from posthepatic tissues. In a second experiment, 3 of the lambs were killed following 4-h infusions of DL[1-13C]HMTBA and [2H3]Met with enrichments monitored in 15 tissues. Only kidney showed [1-13C]Met enrichment higher than plasma, which suggests that it must be a primary source of plasma Met derived from HMTBA. Based on comparison of plasma and intracellular [1-13C]:[2H3]Met enrichments, all tissues synthesized Met from HMTBA but to significantly different extents. The lowest values were for muscle, skin, brain, and lung; intermediate conversions occurred in rumen, omasum, abomasum, duodenum, jejunum, ileum, and cecum; and the greatest synthesis, equivalent to 22 to 24% of Met entry into cells, was observed for liver and kidney. Therefore, although liver and kidney both converted HMTBA to Met, it was retained by the former and exported by the latter. Under these experimental conditions, synthesis of Met from HMTBA completely eliminated use of dietary Met.

AB - Absorption and metabolism of the Met hydroxy analog 2-hydroxy-4-methylthiobutyrate (HMTBA) was examined using stable isotopes. In the first trial, Dl[1-13C]HMTBA was infused for 6 h (7.4 micromol/min) into the abomasum, and [2H3]Met was infused into the mesenteric vein, of 4 lambs prepared with vascular catheters across the splanchnic bed. Daily, lambs were offered 35 g of a mixed forage-concentrate feed/kg. Recovery of HMTBA at the portal vein was 87%, and of this, 63% bypassed the liver. In contrast, hepatic extraction of Met equaled or exceeded net absorption. Only small quantities of Met synthesized from HMTBA were exported from either the digestive tract or liver, but there was substantial and significant input from posthepatic tissues. In a second experiment, 3 of the lambs were killed following 4-h infusions of DL[1-13C]HMTBA and [2H3]Met with enrichments monitored in 15 tissues. Only kidney showed [1-13C]Met enrichment higher than plasma, which suggests that it must be a primary source of plasma Met derived from HMTBA. Based on comparison of plasma and intracellular [1-13C]:[2H3]Met enrichments, all tissues synthesized Met from HMTBA but to significantly different extents. The lowest values were for muscle, skin, brain, and lung; intermediate conversions occurred in rumen, omasum, abomasum, duodenum, jejunum, ileum, and cecum; and the greatest synthesis, equivalent to 22 to 24% of Met entry into cells, was observed for liver and kidney. Therefore, although liver and kidney both converted HMTBA to Met, it was retained by the former and exported by the latter. Under these experimental conditions, synthesis of Met from HMTBA completely eliminated use of dietary Met.

KW - Abomasum

KW - Absorption

KW - Animals

KW - Carbon Isotopes

KW - Catheterization

KW - Diet

KW - Isotope Labeling

KW - Kidney

KW - Liver

KW - Mesenteric Veins

KW - Methionine

KW - Organ Specificity

KW - Portal Vein

KW - Sheep

U2 - 10.3168/jds.S0022-0302(06)72175-0

DO - 10.3168/jds.S0022-0302(06)72175-0

M3 - Article

C2 - 16507704

VL - 89

SP - 1072

EP - 1080

JO - Journal of Dairy Science

JF - Journal of Dairy Science

SN - 0022-0302

IS - 3

ER -