Belakovskiĭ M S, Khaĭdakov M S
Kosm Biol Aviakosm Med. 1989 Nov-Dec;23(6):36-9.
Rats were for 6 weeks either kept in small cages or suspended. The caged rats showed hypocalcemia and lowered active transport of calcium in the intestine and no changes of PTH in blood. Femoral bone measurements in these rats revealed reduced density and content of calcium and phosphorus in proximal epiphyses, slight increase of these parameters in diaphyses and lack of changes in distal epiphyses. The suspended rats exhibited normocalcemia, noticeable but insignificant increase of PTH and calcium absorption as well as decreased density and content of calcium and phosphorus in distal epiphyses and their slight increase in diaphyses. Administration of active vitamin D3 metabolites led to an increase of bone mineral density and content only in those femur compartments where hypokinesia-induced changes were seen. It is concluded that during hypokinesia bone disorders are predominantly produced by local factors that may increase bone sensitivity to systemic influences.
将大鼠置于小笼中饲养或悬吊6周。笼养大鼠出现低钙血症，肠道钙的主动转运降低，血液中甲状旁腺激素（PTH）无变化。对这些大鼠股骨的测量显示，近端骨骺的钙和磷密度及含量降低，骨干中这些参数略有增加，远端骨骺无变化。悬吊大鼠表现为血钙正常，PTH和钙吸收有明显但不显著的增加，远端骨骺的钙和磷密度及含量降低，骨干中略有增加。给予活性维生素D3代谢物仅导致那些出现运动减少诱导变化的股骨部位骨矿物质密度和含量增加。得出的结论是，在运动减少期间，骨骼疾病主要由局部因素引起，这些局部因素可能会增加骨骼对全身影响的敏感性。
