title: Zinc stimulates protein synthesis in the femoral-metaphyseal tissues of normal and skeletally unloaded rats.
abstract: The effect of zinc on protein synthesis in the femoral-metaphyseal tissues of normal and skeletally unloaded rats was investigated. Skeletal unloading was designed using the model of hindlimb suspension in rats. Animals were fed for 2 or 4 days during the unloading. [3H]Leucine was added to the reaction mixture containing the 5500 g supernatant fraction of the homogenate prepared from the femoral-metaphyseal tissues. In vitro protein synthesis was significantly decreased in the bone tissues from the rats which had undergone unloading for 2 or 4 days. When the metaphyseal tissues were cultured for 24 h in the presence of zinc sulfate (10(-5) M) or beta-alanyl-L-histidinato zinc (AHZ, 10(-5) M), zinc compounds clearly stimulated protein synthesis in the metaphyseal tissues from the 4-day unloaded rats. The zinc effect was also seen in the metaphyseal tissues from normal rats. The addition of zinc sulfate (10(-5) M) or AHZ (10(-7) to 10(-5) M) into the reaction mixture containing the 5500 g supernatant fraction of metaphyseal homogenate from normal or unloaded rats produced a significant increase in protein synthesis. This increase was clearly inhibited in the presence of cycloheximide (10(-7) M). The present result demonstrates that protein synthesis is impaired in the femoral-metaphyseal tissues of rats with skeletal unloading, and that this impairment is clearly restored by zinc supplementation.
authors.affiliation: Laboratory of Endocrinology and Molecular Metabolism, Graduate School of Nutritional Sciences, University of Shizuoka, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Ehara
authors.forename: M
authors.initials: M
authors.lastname: Yamaguchi
mesh_terms: D000818:Animals; D000897:Anti-Ulcer Agents / Q000494:pharmacology; D001846:Bone Development; D001851:Bone Diseases, Metabolic / Q000209:etiology / Q000378:metabolism*; D002336:Carnosine / Q000031:analogs & derivatives / Q000494:pharmacology; D002478:Cells, Cultured; D046508:Culture Techniques; D003513:Cycloheximide / Q000494:pharmacology; D018483:Diaphyses / Q000378:metabolism; D005260:Female; D005269:Femur / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D019417:Hindlimb Suspension / Q000009:adverse effects; D009942:Organometallic Compounds / Q000494:pharmacology; D014176:Protein Biosynthesis; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D015032:Zinc / Q000378:metabolism*; D017967:Zinc Compounds / Q000032:analysis / Q000494:pharmacology*
chemical_list: D000897:Anti-Ulcer Agents; D009942:Organometallic Compounds; D011500:Protein Synthesis Inhibitors; D017967:Zinc Compounds; C061957:polaprezinc; D002336:Carnosine; D003513:Cycloheximide; D015032:Zinc