Increase in bone protein components with healing rat fractures: enhancement by zinc treatment.
The alteration in bone components in the femoral-diaphyseal tissues with fracture healing was investigated. Rats were sacrificed 7 and 14 days after the femoral fracture. Protein content in the femoral-diaphyseal tissues was markedly elevated by fracture healing. Analysis with sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that many protein molecules were induced in the diaphyseal tissues with fracture healing. Moreover, when the femoral-diaphyseal tissues with fracture healing were cultured for 24 and 48 h in a serum-free medium, many proteins in the bone tissues were released into the medium. Also, the culture of the diaphyseal tissues with fracture healing caused a significant increase in bone alkaline phosphatase activity and deoxyribonucleic acid (DNA) content. Meanwhile, the presence of zinc acexamate (10-5 and 10-4 M), a stimulator of bone formation, in a culture medium induced a significant elevation of protein content and alkaline phosphatase activity in the diaphyseal tissues with fracture healing. Such an effect was completely abolished by the presence of cycloheximide (10-6 M), an inhibitor of protein synthesis. The present study suggests that fracture healing induces a newly synthesized bone protein component including stimulatory factor(s) for bone formation. Zinc supplementation may stimulate the healing of femoral fracture.
Igarashi
A
A
Laboratory of Endocrinology and Molecular Metabolism, Graduate School of Nutritional Sciences, University of Shizuoka, Shizuoka 422-8526, Japan.
Yamaguchi
M
M
D000469:Alkaline Phosphatase / Q000032:analysis; D000614:Aminocaproates; D015119:Aminocaproic Acid / Q000494:pharmacology / Q000627:therapeutic use; D000818:Animals; D015415:Biomarkers; D003513:Cycloheximide / Q000494:pharmacology; D004247:DNA / Q000032:analysis; D005264:Femoral Fractures / Q000188:drug therapy* / Q000378:metabolism; D017102:Fracture Healing / Q000187:drug effects*; D008297:Male; D009924:Organ Culture Techniques; D010006:Osteoblasts / Q000187:drug effects; D010024:Osteoporosis / Q000517:prevention & control; D014176:Protein Biosynthesis; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar
D000614:Aminocaproates; D015415:Biomarkers; D011500:Protein Synthesis Inhibitors; C018802:6-acetylaminocaproic acid; D004247:DNA; D003513:Cycloheximide; D000469:Alkaline Phosphatase; D015119:Aminocaproic Acid