Eigenmann J E, Eigenmann R Y
Acta Endocrinol (Copenh). 1981 Dec;98(4):514-20. doi: 10.1530/acta.0.0980514.
A sensitive radioimmunoassay (RIA) for canine growth hormone (GH) was developed. Antibodies were elicited in rhesus monkeys. One antiserum exhibited a working titer at a dilution of 1: 500 000. Radioiodination was performed enzymatically employing lactoperoxidase. Logit-log transformation and least squares fitting resulted in straight line fitting of the standard curve between 0.39 and 50 ng/ml. Formation of large-molecular [125I]GH during storage caused diminished assay sensitivity. Therefore [125I]GH was re-purified by gel chromatography. Using this procedure, high and reproducible assay sensitivity was obtained. Tracer preparations were used for as long as 3 months after iodination. Diluted plasma from normal and acromegalic dogs resulted in a dose-response curve parallel to the standard curve. Canine prolactin exhibited a cross-reactivity of 2%. The within-assay coefficient of variation (CV) was 3.8 and the between-assay CV was 7.2%. Mean plasma GH concentration in normal dogs was 1.92 +/- 0.14 ng/ml (mean +/- SEM). GH levels in acromegalic dogs were appreciably higher. Insulin-induced hypoglycaemia, arginine and ornithine administration resulted in inconsistent and sluggish GH increment. A better response was obtained by injecting a low dose of clonidine. Clonidine administration to hypopituitary dogs resulted in absent or poor GH increment.
开发了一种用于犬生长激素（GH）的灵敏放射免疫测定法（RIA）。在恒河猴体内诱发产生抗体。一种抗血清在1:500 000的稀释度下表现出有效效价。采用乳过氧化物酶进行酶促放射性碘化。通过对数-对数转换和最小二乘法拟合，在0.39至50 ng/ml之间得到标准曲线的直线拟合。储存期间大分子[125I]GH的形成导致测定灵敏度降低。因此，通过凝胶色谱法对[125I]GH进行了重新纯化。使用该方法，获得了高且可重复的测定灵敏度。碘化后，示踪剂制剂可使用长达3个月。来自正常犬和肢端肥大症犬的稀释血浆产生了与标准曲线平行的剂量反应曲线。犬催乳素的交叉反应率为2%。批内变异系数（CV）为3.8%，批间CV为7.2%。正常犬的平均血浆GH浓度为1.92±0.14 ng/ml（平均值±标准误）。肢端肥大症犬的GH水平明显更高。胰岛素诱导的低血糖、精氨酸和鸟氨酸给药导致GH升高不一致且迟缓。注射低剂量可乐定可获得更好的反应。对垂体功能减退犬给予可乐定导致GH升高缺失或不佳。
