title: Whole-body synthesis of L-homoarginine in pigs and rats supplemented with L-arginine.
abstract: Recent studies suggest an important role for L-homoarginine in cardiovascular, hepatic and neurological functions, as well as the regulation of glucose metabolism. However, little is known about whole-body L-homoarginine synthesis or its response to dietary L-arginine intake in animals. Four series of experiments were conducted to determine L-homoarginine synthesis and catabolism in pigs and rats. In Experiment 1, male and female pigs were fed a corn- and soybean meal-based diet supplemented with 0.0-2.42 % L-arginine-HCl. In Experiment 2, male and female rats were fed a casein-based diet, while receiving drinking water containing supplemental L-arginine-HCl to provide 0.0-3.6 g L-arginine/kg body-weight/day. In both experiments, urine collected from the animals for 24 h was analyzed for L-homoarginine and related metabolites. In Experiment 3, pigs and rats received a single oral dose of 1 or 10 mg L-homoarginine/kg body-weight, respectively, and their urine was collected for 24 h for analyses of L-homoarginine and related substances. In Experiment 4, slices of pig and rat tissues (including liver, brain, kidney, heart, and skeletal-muscle) were incubated for 1 h in Krebs-bicarbonate buffer containing 5 or 50 µM L-homoarginine. Our results indicated that: (a) animal tissues did not degrade L-homoarginine in the presence of physiological concentrations of other amino-acids; (b) 95-96 % of orally administered L-homoarginine was recovered in urine; (c) L-homoarginine was quantitatively a minor product of L-arginineg catabolism in the body; and (d) dietary L-arginine supplementation dose-dependently increased whole-body L-homoarginine synthesis. These novel findings provide a new framework for future studies of L-homoarginine metabolism and physiology in animals and humans.
authors.affiliation: Hubei Key Laboratory of Animal Nutrition and Feed Science, Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety,, Wuhan Polytechnic University, Wuhan, 430023, China.|Department of Animal Science, Texas A&M University, College Station, TX, 77843, USA.
authors.forename: Yongqing
authors.initials: Y
authors.lastname: Hou
authors.affiliation: Department of Animal Science, Texas A&M University, College Station, TX, 77843, USA.
authors.forename: Shengdi
authors.initials: S
authors.lastname: Hu
authors.affiliation: Department of Animal Science, Texas A&M University, College Station, TX, 77843, USA.
authors.forename: Sichao
authors.initials: S
authors.lastname: Jia
authors.affiliation: Department of Animal Science, Texas A&M University, College Station, TX, 77843, USA.
authors.forename: Gayan
authors.initials: G
authors.lastname: Nawaratna
authors.affiliation: Department of Animal Science, Texas A&M University, College Station, TX, 77843, USA.
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Che
authors.affiliation: Department of Animal Science, Texas A&M University, College Station, TX, 77843, USA.
authors.forename: Fenglai
authors.initials: F
authors.lastname: Wang
authors.affiliation: Department of Animal Science, Texas A&M University, College Station, TX, 77843, USA.
authors.forename: Fuller W
authors.initials: FW
authors.lastname: Bazer
authors.affiliation: Hubei Key Laboratory of Animal Nutrition and Feed Science, Hubei Collaborative Innovation Center for Animal Nutrition and Feed Safety,, Wuhan Polytechnic University, Wuhan, 430023, China. g-wu@tamu.edu.|Department of Animal Science, Texas A&M University, College Station, TX, 77843, USA. g-wu@tamu.edu.
authors.forename: Guoyao
authors.initials: G
authors.lastname: Wu
mesh_terms: D000821:Animal Feed; D000818:Animals; D001120:Arginine / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000097:blood / Q000378:metabolism* / Q000652:urine; D001835:Body Weight / Q000187:drug effects; D003404:Creatinine / Q000652:urine; D019587:Dietary Supplements; D005260:Female; D006709:Homoarginine / Q000008:administration & dosage / Q000096:biosynthesis* / Q000652:urine; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013025:Glycine max / Q000737:chemistry; D013552:Swine; D003313:Zea mays / Q000737:chemistry; D019323:omega-N-Methylarginine / Q000097:blood / Q000652:urine
chemical_list: D006709:Homoarginine; D019323:omega-N-Methylarginine; C024917:symmetric dimethylarginine; C018524:N,N-dimethylarginine; D001120:Arginine; D003404:Creatinine
keywords: Animals; Arginine; Homoarginine; Metabolism; Synthesis