Trow R S, Klingensmith G J, Klingensmith W C, Huffer W E, Schalch D S
J Nucl Med. 1983 Mar;24(3):224-7.
We have investigated the uptake of Tc-99m methylene diphosphonate (Tc-MDP) in the metaphysis and shaft of the rat femur as affected by hypophysectomy and hormonal replacement with growth hormone and thyroxine. Two hours following injection of Tc-MDP, the metaphysis and a specimen of shaft were obtained and the metaphysis-to-shaft radioactivity ratio was measured. By five days after hypophysectomy the metaphysis-to-shaft ratio fell from a control value of 3.8 +/- 0.2 (mean +/- s.e.) to 2.4 +/- 0.2 (p less than 0.05) and remained significantly decreased throughout the 30-day study. When daily hormonal replacement with 0.5 mg of bovine growth hormone and 10 micrograms of thyroxine (both administered intraperitoneally) was given, beginning on the eighth day after hypophysectomy, the metaphysis-to-shaft ratio of Tc-MDP returned to control levels in twelve days. This model demonstrates the effect of growth hormone and thyroxine on the distribution of Tc-MDP, and may be useful as a radiobioassay of net circulating skeletal growth-promoting activity.
我们研究了垂体切除以及用生长激素和甲状腺素进行激素替代对大鼠股骨干骺端和骨干摄取锝-99m亚甲基二膦酸盐（Tc-MDP）的影响。注射Tc-MDP两小时后，获取干骺端和一段骨干标本，并测量干骺端与骨干的放射性比值。垂体切除术后五天，干骺端与骨干的比值从对照值3.8±0.2（均值±标准误）降至2.4±0.2（p＜0.05），且在整个30天的研究过程中一直显著降低。从垂体切除术后第八天开始，每天腹腔注射0.5毫克牛生长激素和10微克甲状腺素进行激素替代，12天后，Tc-MDP的干骺端与骨干比值恢复到对照水平。该模型证明了生长激素和甲状腺素对Tc-MDP分布的影响，可用作循环中促进骨骼生长净活性的放射性生物测定。
