Catherwood B D, Friedler R M, Singer F R
Endocrinology. 1976 Jan;98(1):228-36. doi: 10.1210/endo-98-1-228.
The sites of clearance of endogenous parathyroid hormone (PTH) were studied in dogs who developed secondary hyperparathyroidism on a vitamin D-deficient diet. Simultaneous blood samples were obtained from the femoral artery, and the hepatic, renal, portal, and femoral veins. Radioimmunoassay of canine immunoreactive PTH (iPTH) in a heterologous bovine PTH (bPTH) system indicated that the kidney and liver extracted 49% and 46%, respectively, of the iPTH circulating through these organs. Characterization of the circulating iPTH in these animals was carried out by gel filtration and radioimmunoassay of the eluant fractions utilizing specific amino- and carboxyl-terminal antisera. The hormone in the peripheral circulation co-eluted with [125I]-iodobPTH and no fragments of iPTH were detected. Immunochemical differences between bovine and canine PTH were detected in the carboxyl-terminal region of the molecule. The results indicate that endogenous PTH in the vitamin D-deficient, hypocalcemic dog is cleared by the kidney and liver and that the predominant form of the hormone in this animal is similar to glandular bPTH 1-84.
在因维生素D缺乏饮食而发生继发性甲状旁腺功能亢进的犬中，研究了内源性甲状旁腺激素（PTH）的清除部位。同时从股动脉、肝静脉、肾静脉、门静脉和股静脉采集血样。在异源牛PTH（bPTH）系统中对犬免疫反应性PTH（iPTH）进行放射免疫测定，结果表明，流经肾脏和肝脏的iPTH分别有49%和46%被这两个器官摄取。利用特异性氨基末端和羧基末端抗血清，通过凝胶过滤和对洗脱级分进行放射免疫测定，对这些动物体内循环的iPTH进行了特性分析。外周循环中的激素与[125I] - 碘代bPTH共洗脱，未检测到iPTH片段。在分子的羧基末端区域检测到牛和犬PTH之间的免疫化学差异。结果表明，维生素D缺乏、血钙过低的犬体内的内源性PTH由肾脏和肝脏清除，且该动物体内激素的主要形式类似于腺源性bPTH 1 - 84。
