A systematic review of metabolism of methionine sources in animals:One parameter does not convey a comprehensive story  

作　　者：Philippe Becquet Mercedes Vazquez-Anon Yves Mercier Karen Wedekind Tahir Mahmood Dolores I.Batonon-Alavo Frances Yan 

机构地区：[1]International Methionine Analogue Association,Regus Brussels City Centre,Stephanie Square,Avenue Louise,65,B-1050 Brussels,Belgium [2]Novus International Inc.,20 Research Park Drive,Saint Charles,Missouri 63304,USA [3]Adisseo France SAS,Antony Parc II,10 Place Du General de Gaulle,Antony 92160,France

出　　处：《Animal Nutrition》2023年第2期31-49,共19页动物营养（英文版）

摘　　要：The goal of this review article,based on a systematic literature search,is to critically assess the state of knowledge and experimental methodologies used to delineate the conversion and metabolism of the 2 methionine(Met)sources DL-methionine(DL-Met)and DL-2-hydroxy-4-(methylthio)butanoic acid(HMTBa).The difference in the chemical structures of HMTBa and DL-Met indicates that these molecules are absorbed and metabolized differently in animals.This review explores the methodologies used to describe the 2-step enzymatic conversion of the 3 enantiomers(D-HMTBa,L-HMTBa and D-Met)to L-Met,as well as the site of conversion at the organ and tissue levels.Extensive work was published documenting the conversion of HMTBa and D-Met into L-Met and,consequently,the incorporation into protein using a variety of in vitro techniques,such as tissue homogenates,cell lines,primary cell lines,and everted gut sacs of individual tissues.These studies illustrated the role of the liver,kidney,and intestine in the con-version of Met precursors into L-Met.A combination of in vivo studies using stable isotopes and infusions provided evidence of the wide conversion of HMTBa to L-Met by all tissues and how some tissues are net users of HMTBa,whereas others are net secreters of L-Met derived from HMTBa.Conversion of D-Met to L-Met in organs other than the liver and kidney is poorly documented.The methodology cited in the literature to determine conversion efficiency ranged from measurements of urinary,fecal,and respiratory excretion to plasma concentration and tissue incorporation of isotopes after intraperitoneal and oral in-fusions.Differences observed between these methodologies reflect differences in the metabolism of Met sources rather than differences in conversion efficiency.The factors affecting conversion efficiency are explored in this paper and are mostly associated with extreme dietary conditions,such as noncommercial crystalline diets that are very deficient in total sulfur amino acids with respect to requirements.Impli-cations

关 键 词：DL-METHIONINE Hydroxy-analog of methionine 2-Hydroxy-4-(methylthio)butanoic acid Conversion METABOLISM Methodology 

分 类 号：S816[农业科学—饲料科学]