title: The growth hormone affects the brain protein synthesis rate in hypophysectomized aged rats.
abstract: The purpose of this study was to determine whether the growth hormone (GH) affects the rate of brain protein synthesis in hypophysectomized aged rats. Experiments were conducted on three groups of 24-wk-old male rats: group 1 were hypophysectomized to reduce the level of plasma GH, group 2 were hypophysectomized and treated with GH and group 3 were sham-operated controls. The fractional rates of protein synthesis in the brains of hypophysectomized rats with GH were significantly greater than those in hypophysectomized rats without GH. In the cerebral cortex and cerebellum, the RNA activity [g protein synthesized/(g RNA.d)] significantly correlated with the fractional rate of protein synthesis (r>0.88, p<0.001). The RNA concentration (mg RNA/ g protein) was also related to the fractional rate of protein synthesis in these organs (r>0.56, p<0.05). The results suggest that the treatment of GH to hypophysectomized aged rats is likely to increase the rate of protein synthesis in the brain, and that RNA activity is at least partly related to the fractional rate of brain protein synthesis.
authors.affiliation: Laboratory of Nutritional Biochemistry, School of Food and Nutritional Sciences, The University of Shizuoka, Shizuoka, Japan.
authors.forename: Miho
authors.initials: M
authors.lastname: Ohsumi
authors.forename: Kazuyo
authors.initials: K
authors.lastname: Tujioka
authors.forename: Kazutoshi
authors.initials: K
authors.lastname: Hayase
authors.forename: Shinichi
authors.initials: S
authors.lastname: Nagata
authors.forename: Hidehiko
authors.initials: H
authors.lastname: Yokogoshi
mesh_terms: D000375:Aging / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000378:metabolism*; D013006:Growth Hormone / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D007016:Hypophysectomy; D008297:Male; D014176:Protein Biosynthesis / Q000187:drug effects*; D012313:RNA / Q000096:biosynthesis / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D012965:Sodium Chloride / Q000008:administration & dosage
chemical_list: D012965:Sodium Chloride; D012313:RNA; D013006:Growth Hormone