Champion Z J, James E A, Vickers M H, Breier B H, Casey P J
Research Centre in Reproductive Medicine, Faculty of Medicine and Health Science, The University of Auckland, Auckland, New Zealand.
Vet J. 2000 Sep;160(2):147-52. doi: 10.1053/tvjl.2000.0485.
The effect of intramuscularly administered recombinant bovine growth hormone (rbGH) on insulin-like growth factor-I (IGF-I) and white and red blood cell indices was studied in Thoroughbred geldings. An insulin-like growth factor binding protein (IGFBP)-blocked radioimmunoassay was modified and validated for the measurement of IGF-I in equine blood plasma. Baseline values of IGF-I and blood indices were determined over a 48 h period and then a single dose of 5 microg/kg, 10 microg/kg or 50 microg/kg of rbGH was administered. Insulin-like growth factor-I levels increased in a dose-dependent manner, with the highest values between 12 h and 24 h. The highest dose (50 microg/kg) yielded the greatest IGF-I response with a 90.2+/-10.8% increase at 24 h. White blood cell count increased following the three doses of rbGH with the highest white blood cell count at 12 h after the 50 microg/kg dose. Haemoglobin was significantly increased at 24 h (P< 0.05), when values following doses of 10 microg/kg and 50 microg/kg were significantly greater than after the vehicle or the dose of 5 microg/kg. Red blood cell count was not affected by any of the rbGH doses. These results indicated that rbGH is biologically active in the horse and that rbGH at a dose rate of 10 microg/kg or more could be used therapeutically.
研究了肌肉注射重组牛生长激素（rbGH）对纯种雄性马胰岛素样生长因子-I（IGF-I）以及白细胞和红细胞指标的影响。对一种胰岛素样生长因子结合蛋白（IGFBP）阻断放射免疫测定法进行了改进和验证，用于测定马血浆中的IGF-I。在48小时内测定IGF-I和血液指标的基线值，然后单次注射5微克/千克、10微克/千克或50微克/千克的rbGH。IGF-I水平呈剂量依赖性升高，在12小时至24小时之间达到最高值。最高剂量（50微克/千克）产生的IGF-I反应最大，在24小时时增加了90.2±10.8%。注射三剂rbGH后白细胞计数增加，50微克/千克剂量后12小时白细胞计数最高。血红蛋白在24小时时显著升高（P<0.05），此时10微克/千克和50微克/千克剂量后的数值显著高于注射赋形剂或5微克/千克剂量后的数值。红细胞计数不受任何rbGH剂量的影响。这些结果表明，rbGH在马体内具有生物活性，10微克/千克或更高剂量率的rbGH可用于治疗。
