A study of osteoprotective effect of l-arginine, l-norvaline and rosuvastatin on a model of hypoestrogen-induced osteoporosis in rats

Effect on the microcirculatory bed of the bony tissue is one of promising approaches to treatment of osteoporosis. Aim. To study anti-osteoporotic properties of endothelioprotectors: L-arginine, L-norvaline and rosuvastatin. Materials and Methods. Osteoprotective properties of L-arginine, L-norvaline and rosuvastatin, and also of a reference drug– strontium ranelate – were studied on 152 female rats of Wistar line using a model of hypoestrogen-induced osteoporosis. Anti-osteoporotic and endothelioprotective effect of the drugs were evaluated by laser dopplerflowmetry (LDF) of the proximal metaphysis of the femoral bone, morphometry of trabeculae of bone, and also by calculation of the coefficient of endothelial dysfunction. Results. LDF showed that maximal increase in microcirculation of the proximal metaphysis of the femoral bone, in comparison with animals with untreated osteoporosis (61.52±3.74 perfusion units, PU) was achieved with L-norvaline (115.25±5.36 PU, p<0.001) and rosuvastatin (106.57±5.22 PU, p<0.001), less expressed effect was demonstrated by L-arginine (98.10±4.48 PU, p<0.001) and a reference drug – strontium ranelate (86.49±4.99 PU). A similar tendency was observed in morphometry of trabeculae of bone: in the group with untreated osteoporosis the diameter of trabeculae was 61.68±1.24 µm, in the group with use fL-norvaline – 91.86±1.8 µm (p<0.001), in the group with use of L-arginine – 86.64±1.39 µm (p<0.001) and in the group with use of strontium ranelate – 89.08±1.09 µm. Conclusion. L-arginine and L-norvaline and also rosuvastatin possess the property of improving a morphofunctional condition of bone tissue and may be recommended for further preclinical study.