Development of the resorption of bone restrainer aiming at clinical application for the child steroid-related jawbone osteoporosis

糖皮质激素用于治疗各种疾病，如严重哮喘、类风湿性关节炎和慢性肾脏疾病，但发病率低。但在治疗6个月或更长时间的患者中，糖皮质激素诱导的骨质疏松症的发生率约为50%。在儿童中，糖皮质激素治疗不仅会导致骨质疏松，而且会导致生长迟缓，但对GC引起的儿童和成年人骨质疏松的下颌骨骨代谢和骨结构的研究还很少。目前广泛用于治疗骨质疏松症的双膦酸盐，根据其化学结构和作用机制分为两大类。含氮双膦酸盐（如risedoronate）是比不含氮双膦酸盐（如依替膦酸盐和氯膦酸盐）更有效的骨吸收抑制剂。本研究旨在观察含氮双膦酸盐对糖皮质激素（GC）诱导的生长期骨质疏松症大鼠胫骨和下颌骨的影响。在松质骨中，利塞膦酸钠可改善GC引起的骨横截面积和骨矿含量的降低。利塞多纳盐可增加骨密度，并通过降低骨转换率形成致密骨微结构。在皮质骨，利塞膦酸钠改善GC诱导的骨横截面积和骨矿物质含量的减少。

Gluocorticoids are used to treat various disease, such as severe asthma ,rheumatioid arthritis, and chronic renal disease,but the incidence rates. But the incidence rate of glucocorticoid-induced osteoporosis is approximately 50% in patients treated for 6 months or longer. In children,not only osteoporosis but also growth retaradation occurred with choronic glucocorticoid therapy.However, little is known about the bone metabolism and bone architecture of the mandible with GC induced osteoporosis in children and adolescens. Bisphosphanate which are widely use to manage adluts with osteoporosis are divided into 2 classes according to their chemical structure and mechanism of action. The nitrogen-containing bisphosphonates ,such as risedoronate ,are markedly more potent inhibitors of osteoclastic bone resorption than nonnitrogen-containing bisphosphonates ,such as etidronate and clodronate. Hover,the effctts of nitrogen-containing bisphosphonates on bone structure and bone formation of the mandible in cases of established GC induced osteoporosis during the growth syage are unknown.The aim of the present study was to estimate the effects of the tibia and mandible in growing rats treaed with t glucocorticoid (GC) 5-wwk-old male Wistar rats were given oral risedoronate were given oral in dose of (saline), 0.5, or 1.0mg/kg/day for 4 weeks following administration of oral predonisolone in dose of 30mg/kg/2days for 6 weeks.In trabecular bone, risedronate improved the GC induced decreases in bone cross-sectional area and bone mineral content. Risedoronate increased bone density and also formed formed dense bone microarchitetecture by reducing in bone turn over rate. In cortical bone ,risedronate improved GC induced decreases in bone cross sectional area and bone mineral content.