Danks J A, Devlin A J, Ho P M, Diefenbach-Jagger H, Power D M, Canario A, Martin T J, Ingleton P M
St Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia.
Gen Comp Endocrinol. 1993 Nov;92(2):201-12. doi: 10.1006/gcen.1993.1156.
Using antibodies to the amino-terminal region of human parathyroid hormone-related protein (PTHrP) we have demonstrated PTHrP immunoreactivity in pituitaries and plasma of the sea bream (Sparus aurata). Pituitary cells at two distinct locations contained immunodetectable PTHrP; an anterior group in the rostral pars distalis which also contained immunoreactive thyroid stimulating hormone (TSH), and a posterior group lying at the border of the pars intermedia and proximal pars distalis between cells which stained with antibody to human corticotrophin-like intermediate lobe peptide. By Western blot analysis pituitary extracts contained two immunoreactive isoforms of PTHrP, one of 29 kDa and the other of 26 kDa. Media of pituitaries incubated for up to 14 days in Krebs-Ringer bicarbonate also had several isoforms of immunodetectable PTHrP, two of them corresponding to the 29- and 26-kDa molecular forms but there were in addition both larger and smaller molecules. The concentration of PTHrP in sea bream plasma was comparable with levels observed in human subjects with humoral hypercalcaemia of malignancy. There was no reaction between pituitary cells or pituitary extracts and antibody to human parathyroid hormone. Thus sea bream pituitary contains immunoreactive PTHrP, which appears to be released into medium during in vitro incubation and which may be a significant source of plasma immunoreactive PTHrP in vivo.
利用针对人甲状旁腺激素相关蛋白（PTHrP）氨基末端区域的抗体，我们在黑鲷（Sparus aurata）的垂体和血浆中证实了PTHrP免疫反应性。两个不同位置的垂体细胞含有可免疫检测到的PTHrP；一组位于吻侧部远侧部的前部，该部位也含有免疫反应性促甲状腺激素（TSH），另一组位于中间部和近端部远侧部边界处，位于用抗人促肾上腺皮质激素样中间叶肽抗体染色的细胞之间。通过蛋白质印迹分析，垂体提取物含有两种PTHrP免疫反应性同工型，一种为29 kDa，另一种为26 kDa。在碳酸氢盐林格氏液中孵育长达14天的垂体培养基中也有几种可免疫检测到的PTHrP同工型，其中两种对应于29 kDa和26 kDa的分子形式，但此外还有更大和更小的分子。黑鲷血浆中PTHrP的浓度与恶性肿瘤体液性高钙血症患者中观察到的水平相当。垂体细胞或垂体提取物与人甲状旁腺激素抗体之间没有反应。因此，黑鲷垂体含有免疫反应性PTHrP，在体外孵育过程中似乎会释放到培养基中，并且可能是体内血浆免疫反应性PTHrP的重要来源。
