Calcitonin-like immunoreactivity in rat and human pituitary glands: histochemical, in vitro, and in vivo studies.
Calcitonin-like immunoreactivity in rat and human pituitary glands: histochemical, in vitro, and in vivo studies.
复制标题
大鼠和人垂体中的降钙素样免疫反应性：组织化学、体外和体内研究。
作者：
C. Cooper;T. Peng;J. Obie;S. C. Garner
本研究旨在确定垂体是否含有与降钙素（CT）抗血清反应的免疫反应性物质，如果是，是否可以证明该物质的分泌。用免疫过氧化物酶法检测了15份抗大鼠和人CT的抗血清，发现2份抗人CT的抗血清可染大鼠垂体，几份抗人CT的抗血清可染人垂体。基本上大鼠中叶中的所有细胞以及大鼠和人前叶中的散在细胞均显示染色，并且通过预先用大鼠或人CT吸附抗血清未完全消除染色。染色大鼠垂体的2种抗血清显示与几种合成人CT片段（1-18、11-23和22-32）的交叉反应性，但与ACTH-（1-39）、ACTH-（1-24）、β-内啡肽、α-或β-MSH或牛促脂素无交叉反应性。两个品系幼鼠垂体粗提物呈CT样免疫反应，RIA法可简便地测定（0.2- 0.3ng/腺体）。在体内，一种抗血清，染色垂体和1，没有进行比较，使用年轻的大鼠高钙（15-20毫克/分升）与静脉钙。在甲状腺的大鼠中，无论垂体是否存在，两种抗血清的血清CT均增加15倍以上。在甲状腺切除大鼠中，即使存在垂体，在高钙血症期间血清CT仍然检测不到（低于50至100 pg/ml）。在体外，大鼠垂体在无血清培养基中不释放可测量量的免疫反应性CT样物质，即使培养基含有高钙（2.5 mM），高钾（25 mM），或TRH（10（-6）M）。因此，该结果与垂体中CT样物质的其他报告一致，但无法证明该物质的分泌。我们假设该材料不是真正的CT，而是可能包含在促肾上腺皮质激素-β-促脂素的31 K前体蛋白中的相关肽序列。
This study was designed to determine whether pituitary glands contain an immunoreactive material which reacts with antisera to calcitonin (CT) and, if so, whether secretion of the material could be demonstrated. Testing 15 antisera to rat and human CT and using an immunoperoxidase method, we found 2 antisera to human CT which stained rat pituitaries and several which stained human pituitaries. Essentially all cells in the rat intermediate lobe and scattered cells in the rat and human anterior lobes showed staining, and staining was not entirely abolished by prior adsorption of antisera with rat or human CT. The 2 antisera which stained rat pituitaries showed cross-reactivity with several synthetic human CT fragments (1-18, 11-23 and 22-32) but not with ACTH-(1-39), ACTH-(1-24), beta-endorphin, alpha- or beta MSH, or bovine lipotropin. Crude extracts of pituitaries from 2 strains of young rats showed CT-like immunoreactivity which could be measured easily by RIA (0.2-0.3 ng/gland). In vivo, an antiserum which stained pituitaries and 1 which did not were compared using young rats made hypercalcemic (15-20 mg/dl) with iv Ca. In rats with thyroids, both antisera showed an increase in serum CT of more than 15-fold whether the pituitary was present or absent. In thyroidectomized rats, serum CT remained undetectable (less than 50 to 100 pg/ml) during hypercalcemia even if the pituitary was present. In vitro, rat pituitaries in a serum-free medium did not release measurable amounts of immunoreactive CT-like material even when medium contained high Ca (2.5 mM), high K (25 mM), or TRH (10(-6) M). Therefore, the findings agree with other reports of a CT-like material in the pituitary, but no secretion of the material could be demonstrated. We hypothesize that the material is not authentic CT but is, rather a related peptide sequence probably contained in the 31 K precursor protein of ACTH-beta-lipotropin.