Characterization of corticotropin-releasing factor receptors in dissociated brain cell cultures.
Characterization of corticotropin-releasing factor receptors in dissociated brain cell cultures.
复制标题
分离脑细胞培养物中促肾上腺皮质激素释放因子受体的表征。
DOI：
10.1016/0006-8993(88)90357-5
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发表时间：
1988
期刊：
影响因子：
2.9
通讯作者：
DeSouza,EB
中科院分区：
文献类型：
--
作者：
Kapcala,LP;DeSouza,EB
虽然促肾上腺皮质激素释放因子（CRF）受体已在整个大脑中被确定，但对CRF受体的调节知之甚少。最近的研究旨在建立一个体外模型来研究CRF受体的调节，结果表明CRF在脑细胞培养中结合。为了验证分离的脑细胞培养物含有CRF受体的假设，并可能为研究其调控提供模型，进行了表征标记CRF结合的研究。将第17天胎鼠下丘脑和下丘脑外前脑（主要是皮质）分离的细胞保存在化学定义的培养基中。我们使用了一种稳定的125i标记的羊CRF类似物，125i - tyr0 -羊CRF (125I-oCRF)，来鉴定和表征CRF受体。虽然在下丘脑和下丘脑外细胞培养中均证实了125i - ocrf的特异性结合，但下丘脑外细胞中CRF受体的浓度要高得多（3-5倍）。结合125i - ocrf在下丘脑外细胞中是饱和的，由高亲和力位点（Kd= 0.51nM）和低亲和力位点（Kd= 17.25nM）组成。用各种CRF片段和类似物从细胞中置换标记的CRF，与垂体和脑匀浆的研究相似。下丘脑外细胞在培养的4至13天内多次研究显示CRF受体的数量增加；第13天CRF受体浓度是第4天的3.5倍。旨在确定CRF受体浓度是否可以被CRF、促肾上腺皮质激素1 - 12、阿托品或CRF拮抗剂调节的研究显示，只有慢性暴露于CRF时，CRF受体浓度才会发生变化（降低36%）。结论：(1)下丘脑外前脑和下丘脑分离的胎鼠脑细胞培养物含有CRF受体；(2) CRF受体在脑细胞中的分布和特征与先前报道的脑和垂体中的分布和特征相似；(3)分离的胎鼠脑细胞培养物可为研究CRF受体的调控提供相对简化的体外模型；(4) CRF下调下丘脑外前脑细胞自身受体。
Although corticotropin-releasing factor (CRF) receptors have been identified throughout the brain, relatively little is known about the regulation of CRF receptors. Recent investigations aimed at developing an in vitro model studying the regulation of CRF receptors demonstrated CRF binding in brain cell cultures. To test hypothesis that dissociated brain cell cultures contain CRF receptors and may provide a model for studying their regulation, studies characterizing binding of labeled CRF were performed. Dissociated cells derived from hypothalamus and extrahypothalamic forebrain (predominantly cortex) of day 17 fetal rats were maintained in chemically defined medium. We used a stable125I-labeled analog of ovine CRF,125I-Tyr0-ovine CRF (125I-oCRF), to identify and characterize CRF receptors. Although specific binding of125I-oCRF was demonstrated in both hypothalamic and extrahypothalamic cell cultures, the concentration of CRF receptors was much greater (3–5 fold) in extrahypothalamic cells. Binding125I-oCRF in extrahypothalamic cells was satturable and was composed of high affinity (Kd= 0.51nM) and low affinity (Kd= 17.25nM) sites. Pharmacological displacement of labeled CRF from cells with a variety of CRF fragments and analogs was similar to that in studies of pituitary and brain homogenates. Extrahypothalamic cells studied at several times between 4 and 13 days in culture revealed an increase in the number of CRF receptors; the concentration of CRF receptors at 13 days was 3.5 times that observed at 4 days. Studies directed toward determining whether CRF receptor concentration could be modulated by CRF, adrenocorticotropic hormone1–12, atropine or a CRF antagonist showed a change (36% decrease) only in response to chronic exposure with CRF. Conclusions: (1) dissociated fetal rat brain cell cultures derived from extrahypothalamic forebrain and hypothalamus contain CRF receptors; (2) CRF receptors in brain cells exhibit a differential distribution and characteristics similar to those previously reported in brain and pituitary; (3) dissociated fetal rat brain cell cultures may provide a relatively simplified in vitro model for studying the regulation of CRF receptors; and (4) CRF down-regulates its own receptor in extrahypothalamic forebrain cells.