Dietary Protein Deficiency Induces Osteoporosis in Aged Male Rats

• DOI: 10.1359/jbmr.2000.15.8.1555
• Publication Date: 2006-04-27T03:20:21Z
• Authors: S. Bourrin; A. Toromanoff; P. Ammann; J. P. Bonjour; R. Rizzoli
• Keywords: Male; 0301 basic medicine; 2. Zero hunger; Aging; Body Weight; Osteocalcin; Rats; Rats, Sprague-Dawley; 03 medical and health sciences; Bone Density; Periosteum; Protein Deficiency; Animals; Osteoporosis; Dietary Proteins; Amino Acids; Bone Resorption; Insulin-Like Growth Factor I

Abstract Low dietary intake is common in elderly males with low femoral neck areal bone mineral density (BMD). To evaluate the selective influence of a low-protein diet pathogenesis osteoporosis and to uncover early late adaptation cells protein deficiency, 8-month-old male rats were pair-fed control (15% casein) or isocaloric (2.5% for 1 7 months. BMD, ultimate strength, stiffness, absorbed energy measured tibia proximal metaphysis diaphysis. After double-labeling, histomorphometric analysis was performed at same sites. Serum osteocalcin, insulin-like growth factor I (IGF-I), urinary deoxypyridinoline excretion measured. In tibia, significantly decreases BMD (12%), cancellous mass (71%), trabecular thickness (Tb.Th; 30%), resulting significant reduction strength (27%). cortical middiaphysis, (9%) enlarges medullary cavity (36%), leading thinning lower mechanical (20%). bone, deficiency transiently depresses formation rate (BFR; 60%), osteoid seam (15%), apposition (MAR; 20%), indicating decrease osteoblast recruitment activity. Cortical loss (15%) results from an imbalance between endosteal modeling drifts impaired BFR (70%). From first week osteocalcin IGF-I levels drop significantly. Bone resorption activity remain unchanged throughout experiment. Protein aged induces thinning, association remodeling impairment levels.