Shambaugh G, Kubek M, Wilber J F
J Clin Endocrinol Metab. 1979 Mar;48(3):483-6. doi: 10.1210/jcem-48-3-483.
TRH immunological and biological activities were found in extracts of human placentas. Eight term placentas delivered by cesarean section were extracted with 2 N acetic acid, followed by glacial acetic acid. Lyophilized samples were resuspended in phosphate-buffered saline. TRH activity, identified in each placental extract by specific RIA, averaged 19.8 +/- 3.3 pg/mg protein. TRH in the placental extracts was similar to synthetic TRH by four criteria. 1) Serial dilutions of placental extracts defined an immunoassay inhibition curve with a slope (-1.93) identical to synthetic TRH (-1.88). 2) When placental extract or synthetic TRH was chromatographed on Sephadex G-10, TRH immunoreactivity was found in similar fractions of the eluate. 3) Both placental extract and synthetic TRH stimulated TSH release from rat pituitaries in vitro. 4) Human serum degraded placental extract and synthetic TRH in a qualitatively similar manner. Placental minces did not accumulate exogenous [3H]TRH, suggesting that the placental TRH may originate endogenously.
在人胎盘提取物中发现了促甲状腺激素释放激素（TRH）的免疫活性和生物学活性。对8例剖宫产分娩的足月胎盘用2N乙酸提取，随后用冰醋酸提取。冻干样品重悬于磷酸盐缓冲盐水中。通过特异性放射免疫分析（RIA）在每个胎盘提取物中鉴定出的TRH活性平均为19.8±3.3 pg/mg蛋白质。胎盘提取物中的TRH在四个标准方面与合成TRH相似。1）胎盘提取物的系列稀释定义了一条免疫分析抑制曲线，其斜率（-1.93）与合成TRH（-1.88）相同。2）当胎盘提取物或合成TRH在葡聚糖凝胶G-10上进行色谱分析时，在洗脱液的相似级分中发现了TRH免疫反应性。3）胎盘提取物和合成TRH在体外均刺激大鼠垂体释放促甲状腺激素（TSH）。4）人血清以定性相似的方式降解胎盘提取物和合成TRH。胎盘碎块不积累外源性[3H]TRH，表明胎盘TRH可能内源性产生。
