title: Indian women of childbearing age do not metabolically conserve arginine as do American and Jamaican women.
abstract: BACKGROUND
  In a previous study in pregnant American women, we reported that arginine flux and nitric oxide synthesis increased in trimester 2. More recently, we reported that Indian women do not increase arginine flux during pregnancy as their American or Jamaican counterparts do.
  
  
  OBJECTIVE
  The purpose of this study was to determine whether Indian women of childbearing age are producing less arginine and/or catabolizing more arginine and therefore have less available for anabolic pathways than do Jamaican and American women.
  
  
  METHODS
  Thirty healthy women aged 28.3 ± 0.8 y from the United States, India, and Jamaica (n = 10/group) were given 6 h primed, constant intravenous infusions of guanidino-¹⁵N₂-arginine, 5,5-²H₂-citrulline, ¹⁵N₂-ornithine, and ring-²H₅-phenylalanine, in addition to primed, oral doses of U-¹³C₆-arginine in both the fasting and postprandial states. An oral dose of deuterium oxide was also given to determine fat-free mass (FFM).
  
  
  RESULTS
  Compared with American women, Indian and Jamaican women had greater ornithine fluxes (μmol · kg fat FFM⁻¹ · h⁻¹) in the fasting and postprandial states (27.3 ± 2.5 vs. 39.6 ± 3.7 and 37.2 ± 2.0, respectively, P = 0.01), indicating greater arginine catabolism. However, Jamaican women had a higher endogenous arginine flux than did Indian and American women in the fasting (66.1 ± 3.1 vs. 54.2 ± 3.1 and 56.1 ± 2.1, respectively, P = 0.01) and postprandial (53.8 ± 2.2 vs. 43.7 ± 4.9 and 42.8 ± 3.1, respectively, P = 0.06) states. As a consequence, Indian women had lower arginine bioavailability (μmol · kg FFM⁻¹ · h⁻¹) in the fasting state (42.0 ± 2.6) than did American (49.9 ± 1.3, P = 0.045) and Jamaican (55.5 ± 3.5, P = 0.004) women, as well as in the postprandial state (40.7 ± 3.5 vs. 51.8 ± 1.2 and 57.5 ± 3.2, respectively, P = 0.001).
  
  
  CONCLUSIONS
  Compared with American and Jamaican women, Indian women of childbearing age have a decreased arginine supply because of increased arginine catabolism without an increase in arginine flux.
authors.affiliation: Section of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, and USDA Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX;
authors.forename: Christina C
authors.initials: CC
authors.lastname: Kao
authors.affiliation: USDA Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX;
authors.forename: Jean W
authors.initials: JW
authors.lastname: Hsu
authors.affiliation: St. John's Research Institute, St. John's National Academy of Health Sciences, Bangalore, India; and.
authors.forename: Pratibha
authors.initials: P
authors.lastname: Dwarkanath
authors.affiliation: USDA Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX;
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Karnes
authors.affiliation: Department of Child and Adolescent Health and.
authors.forename: Tameka M
authors.initials: TM
authors.lastname: Baker
authors.affiliation: USDA Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX;
authors.forename: Kurt M
authors.initials: KM
authors.lastname: Bohren
authors.affiliation: Tropical Metabolism Research Unit, University of the West Indies, Mona, Kingston, Jamaica.
authors.forename: Asha
authors.initials: A
authors.lastname: Badaloo
authors.affiliation: Department of Child and Adolescent Health and.
authors.forename: Minerva M
authors.initials: MM
authors.lastname: Thame
authors.affiliation: St. John's Research Institute, St. John's National Academy of Health Sciences, Bangalore, India; and.
authors.forename: Anura V
authors.initials: AV
authors.lastname: Kurpad
authors.affiliation: USDA Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX; fjahoor@bcm.edu.
authors.forename: Farook
authors.initials: F
authors.lastname: Jahoor
mesh_terms: D000328:Adult; D001120:Arginine / Q000031:analogs & derivatives / Q000096:biosynthesis / Q000378:metabolism*; D001823:Body Composition; D002247:Carbon Isotopes; D002956:Citrulline / Q000378:metabolism; D003903:Deuterium; D004734:Energy Metabolism; D005260:Female; D006801:Humans; D007194:India; D007201:Indicator Dilution Techniques; D007563:Jamaica; D062407:Meals; D008954:Models, Biological; D009587:Nitrogen Isotopes; D009751:Nutritional Requirements / Q000208:ethnology*; D009952:Ornithine / Q000378:metabolism; D010649:Phenylalanine / Q000378:metabolism; D013781:Texas
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; C498113:guanidinoarginine; D002956:Citrulline; D010649:Phenylalanine; D001120:Arginine; D003903:Deuterium; D009952:Ornithine
keywords: American; Indian women; Jamaican; arginase; arginine