title: Protein metabolism in growth hormone deficiency, and effects of growth hormone replacement therapy.
abstract: The effects of growth hormone (GH) treatment on protein metabolism were studied in adults with GH deficiency (GHD). A double-blind, placebo-controlled trial of recombinant human GH, 0.018 IU/kg/day for 1 month followed by 0.036 IU/kg/day for 1 month, was performed with isotopic whole-body protein turnover studies at 0 and 2 months. In all, 18 adults with GHD (9 men, 9 women; mean age, 46.6 years; range, 30-56 years) were studied. Whole-body isotopic leucine turnover using L-[1-13C]leucine was assessed by measuring leucine Ra (a measure of protein degradation), non-oxidative leucine Rd (a measure of protein synthesis) and leucine oxidation rate. Lean body mass and circulating insulin-like growth factor I were significantly (p < 0.02) increased at 2 months in the GH-treated group, but not in the placebo group. There was no change in leucine Ra in either the placebo or GH-treated groups at 2 months. Leucine oxidation decreased (p < 0.01) and non-oxidative leucine Rd increased (p < 0.02) in the GH-treated group at 2 months. There was no significant change in either leucine oxidation or non-oxidative leucine Rd in the placebo group at 2 months. These results indicate that the increase in lean body mass resulting from GH treatment in adults with GHD is due to an increase in protein synthesis.
authors.affiliation: Division of Endocrinology and Medicine, United Medical School, Guy's Hospital, London, UK.
authors.forename: D L
authors.initials: DL
authors.lastname: Russell-Jones
authors.forename: A J
authors.initials: AJ
authors.lastname: Weissberger
authors.forename: S B
authors.initials: SB
authors.lastname: Bowes
authors.forename: J M
authors.initials: JM
authors.lastname: Kelly
authors.forename: M
authors.initials: M
authors.lastname: Thomason
authors.forename: A M
authors.initials: AM
authors.lastname: Umpleby
authors.forename: R H
authors.initials: RH
authors.lastname: Jones
authors.forename: P H
authors.initials: PH
authors.lastname: Sönksen
mesh_terms: D000328:Adult; D004311:Double-Blind Method; D005260:Female; D013006:Growth Hormone / Q000172:deficiency* / Q000627:therapeutic use*; D006801:Humans; D007018:Hypopituitarism / Q000188:drug therapy* / Q000378:metabolism; D007930:Leucine / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011506:Proteins / Q000187:drug effects / Q000378:metabolism*; D011994:Recombinant Proteins / Q000627:therapeutic use
chemical_list: D011506:Proteins; D011994:Recombinant Proteins; D013006:Growth Hormone; D007930:Leucine