The severe osteopenia induced by ovariectomy and a low protein intake

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

Viena, Austria

Simposio; 36th European Symposium on Calcified Tissues; 2009

ECTS

  Previously we found that a low dietary protein intake in OVX rats induce a severe osteopenia. In the present study we investigated the effect of anticatabolic treatment with the aminobisphosphonate, olpadronate (OPD) in rats feeding a low protein, normal calcium diet. A total of 30 Wistar adult rats (300±50 g) were studied, 20 rats were ovariectomized (OVX) and 10 were SHAM operated. During 15 days post-surgery all rats were fed a commercial diet (Granave SA, Bs.As.) which supplied protein 15%, vitamin D 200UI% and 0.6% calcium. After that rats were divided in 4 groups and for an additional 60 days they received:G1: OVX + 2.5% casein diet.G2: OVX + 2.5% casein diet + 8ug OPD/100g rats one a week (intraperitoneally) .G3: SHAM + comercial diet (protein 15%)At baseline (Tb) and at the end of the experience (Tf) total skeleton bone mineral content (BMC: mg) and density (BMD: mg/cm2)) were measured by DXA (Small animal Software, Lunar DPX). Proximal tibia BMD (BMDpt) was evaluated using a specific ROI and changes in BMC and BMDpt between Tf and Tb was calculated (Ch.BMC and Ch.BMDpt, respectively). Serum calcium (Ca: mg/dl), phosphorus, bone alkaline fosfatase (bALP: IU/L) and osteocalcin (BGP: ng/ml) were also evaluated. At Tf bone volume of tibia (BV/TV: %) was measured by histology. Results (mean± standard error):TableDifferent letters indicates a: p<0.05The OVX and low protein intake reduced serum Ca and BGP as well as BV/TV and increase serum bAL and BMC and BMDpt compared to SHAM group. OPD treatment reduced serum bAL, Ca an BGP and increased BMC, BMDpt and BV/VT compared to untreated group. However, the treatment with OPD did not reach the bone mass parameters observed in SHAM group. Conclusions: The severe osteopenia induce by OVX and a low protein intake was reduced by OPD treatment. Grant PIP6843.CONICET s3><s5> Conflict of Interest: none declared </s5> Submitter´s email: snzeni@hotmail.com