Experimental models of nutritional deficiencies and hormonal status that influence bone mass.

MAROTTE C; GONZALES CHAVES MMS; PELLEGRINI GG; MANDALUNIS P; FRIEDMAN SM; ZENI SN

Buenos Aires

Congreso; XXVI Reunión Anual de la Asociación Argentina de Osteología y Metabolismo Mineral (AAOMM); 2009

Asociación Argentina de Osteología y Metabolismo Mineral (AAOMM)

Experimental models of nutritional deficiencies and hormonal status that influence bone mass Marotte C1 4, Gonzales Chaves M1 3 4, Pellegrini G1 3, Mandalunis P2, Friedman S3, Zeni S1 3 4 1 Sec. Osteopatías Méd. Hosp. de Clínicas, UBA. 2 Cát. Histología. FOUBA, 3 Cát. Bioquímica Gral y Bucal. FOUBA, 4 CONICET Elderly people often had a low food intake and sun exposure which could contribute to the high prevalecence of osteopenia and fracture risk observed in this population. To evaluate the influence of the low protein intake and/or vitamin D (vit D) status in the patogenesis of osteoporosis we developed the present experimental models. Wistar rats (300±50 g) were OVX (n=20) or SHAM operated (n=20). During 15 days post-surgery all rats were fed a diet containing 15% protein and 200IU% of vit. D. Then, rats were divided into 5 groups, fed a specified diet during an additional period of 45 days: G1: SHAM+15% casein and 200IU% vit D (control); G2: SHAM+2.5% casein and 200IU% vit D; G3: SHAM+2.5% casein and 0IU% vit D; G4: OVX+2.5% casein and 200IU% vit D; G5: OVX+2.5% casein and 0IU% vit D Total skeleton BMD and BMC (BMDet and BMCet, respectively) were measured by DXA (Lunar), BMD of proximal tibia (BMDtp) was evaluated and serum Ca, 25OHD, bALP and BGP were determined at baseline and at the end of the study (Tf). At Tf tibias were removed to measure total bone volume (BV/TV %) histologicaly. Results (mean±SE), G1 to G5, respectively: 25OHD(ng/dl): 29,4±6,1a; 50,0±0,2b; 29,4±1,5a; 8,6±2,5c; 10,3±4,5c. Cas(mg/dl): 10,00±0,2a; 10,0±0,1a; 9,9±0,6a; 9,3±0,1b; 9,8±0,1a. BALP(IU/l): 39,7±5,4a; 39,7±4,6a; 58,0±4,9b; 57,0±4,0b; 66,4±6,5b. BMDet(mg): 2,3±0,3a; 2,0±0,3a; 0,4±0,4b; 0,5±0,1b; 0,2±0,2c. CMOtp(mg/cm2): 55,0±16,2a; 23,0±10,1b; -25,8±11,7c;  -3,0±0,4d; -40,7±13,7e. BV/TV(%): 25,0±4,0a; 9,4±1,4b; 3,1±1,5c, 5,3±2,6c; 1,0±0,4d. Different letters correspond to p<0.05 The negative changes observed in bone mass and bone volume paralleled the increment of defficiencies