Pytlik Maria, Cegieła Urszula, Folwarczna Joanna, Janiec Waldemar, Pytlik Wojciech
Department of Pharmacology, Silesian Medical University, Jagiellońska 4, PL 41-200 Sosnowiec, Poland.
Pol J Pharmacol. 2004 May-Jun;56(3):345-52.
Skeletal disorders occurring in experimental model of osteopenia caused by bilateral ovariectomy in rats are similar to those observed in postmenopausal women. Retinol is a commonly used vitamin, especially by elderly people. The role of retinol in bone remodeling is not well-established. The aim of the present study was to investigate the effect of retinol administered at doses of 700 IU/kg p.o. daily and 3500 IU/kg p.o. daily for 28 days on the development of osteopenia induced by bilateral ovariectomy in 3-month-old Wistar rats. The experiments were carried out on 4 groups of animals: I (C)--sham-operated control rats, II (OVX)--ovariectomized control rats, III (OVX + R700)--OVX rats treated with retinol (700 IU/kg p.o. daily), IV (OVX + R3500)--OVX rats treated with retinol (3500 IU/kg p.o. daily). Body mass gain, bone mass, mineral and calcium content in the tibia, femur and L-4 vertebra, histomorphometric parameters of the right tibia (width of osteoid, periosteal and endosteal transverse growth, the area of the transverse cross section of the bone marrow and cortical bone) and the right femur (width of epiphyseal and metaphyseal trabeculae, width of epiphyseal cartilage), and mechanical properties of the femur were investigated. Bilateral ovariectomy induced osteopenic skeletal changes in mature female rats. Retinol at doses of 700 IU/kg p.o. daily and 3500 IU/kg p.o. daily decreased bone mass (statistically significantly after treatment with 3500 IU/kg p.o. daily). Retinol at both doses caused statistically significant increases in the width of periosteal osteoid, and, at a dose of 3500 IU/kg p.o. daily, of endosteal osteoid. The increase in the width of osteoid may be the effect of disorder of its mineralization, as the decreases in bone mineral and calcium content were also noted. In mechanical tests of the femur, dose-dependent decreases in the ultimate load, the breaking load and the deformation caused by the applied load were observed after administration of retinol (in comparison with the OVX control rats). Concluding, retinol (especially administered at the dose of 3500 IU/kg daily) intensified the changes in the osseous system caused by estrogen deficiency in rats.
大鼠双侧卵巢切除所致骨质减少实验模型中出现的骨骼疾病与绝经后女性所观察到的相似。视黄醇是一种常用维生素，尤其受老年人青睐。视黄醇在骨重塑中的作用尚未完全明确。本研究旨在探讨每日口服剂量为700 IU/kg和3500 IU/kg的视黄醇连续28天对3月龄Wistar大鼠双侧卵巢切除所致骨质减少发展的影响。实验在4组动物上进行：I组（C）——假手术对照大鼠；II组（OVX）——卵巢切除对照大鼠；III组（OVX + R700）——用视黄醇（每日口服700 IU/kg）治疗的OVX大鼠；IV组（OVX + R3500）——用视黄醇（每日口服3500 IU/kg）治疗的OVX大鼠。研究了体重增加、胫骨、股骨和L-4椎骨的骨量、矿物质和钙含量、右胫骨（类骨质宽度、骨膜和骨内膜横向生长、骨髓和皮质骨横截面积）和右股骨（骨骺和干骺端小梁宽度、骨骺软骨宽度）的组织形态计量学参数以及股骨的力学性能。双侧卵巢切除在成年雌性大鼠中诱发了骨质减少的骨骼变化。每日口服剂量为700 IU/kg和3500 IU/kg的视黄醇降低了骨量（每日口服3500 IU/kg治疗后具有统计学显著性）。两种剂量的视黄醇均导致骨膜类骨质宽度具有统计学显著性增加，且每日口服剂量为3500 IU/kg时，骨内膜类骨质宽度也增加。类骨质宽度增加可能是其矿化紊乱的结果，因为同时也观察到骨矿物质和钙含量降低。在股骨力学测试中，给予视黄醇后（与OVX对照大鼠相比）观察到极限负荷、断裂负荷和施加负荷引起的变形呈剂量依赖性降低。总之，视黄醇（尤其是每日剂量为3500 IU/kg时）加剧了大鼠雌激素缺乏所致的骨骼系统变化。
