Kawano S, Kanda K, Ohmori S, Izumi R, Yasukawa K, Murata Y, Seo H
Department of Endocrinology and Metabolism, Nagoya University, Japan.
Environ Med. 1997 Dec;41(2):89-92.
Rat tail-suspension induces disuse atrophy of muscles and bones in hindlimbs. In the present investigation we studied how ovariectomy and estrogen substitution affect the development of the disuse atrophy induced by suspension. Five-week old female Wistar rats were ovariectomized and divided into two groups. One group received intramuscular injection of estradiol dipropionate once a week (OVX-E2 group), and the other received a vehicle injection (OVX group). After the third injection, each group was further divided into two groups, tail-suspended and non-suspended. After 7 days of tail-suspension, a significant decrease in the wet weight of femurs and their Ca and Pi content was observed in the OVX group. However, no significant change in those parameters was observed in the E2 group. In both E2 and OVX groups, a significant decrease in the wet weight of soleus and gastrocnemius muscles was demonstrated after the suspension. This demonstrated that estrogen administration to ovariectomized rats prevents the development of disuse bone atrophy but not that of muscle atrophy, suggesting that estrogen plays important roles in bone remodeling.
尾部悬吊会导致后肢肌肉和骨骼的废用性萎缩。在本研究中，我们研究了卵巢切除和雌激素替代如何影响由悬吊诱导的废用性萎缩的发展。将5周龄的雌性Wistar大鼠进行卵巢切除，并分为两组。一组每周接受一次肌肉注射二丙酸雌二醇（OVX-E2组），另一组接受载体注射（OVX组）。第三次注射后，每组再进一步分为两组，即尾部悬吊组和非悬吊组。尾部悬吊7天后，OVX组的股骨湿重及其钙和磷含量显著降低。然而，E2组的这些参数未观察到显著变化。在E2组和OVX组中，悬吊后比目鱼肌和腓肠肌的湿重均显著降低。这表明给去卵巢大鼠施用雌激素可预防废用性骨萎缩的发展，但不能预防肌肉萎缩的发展，提示雌激素在骨重塑中起重要作用。
