Characterization of cholecystokinin binding sites in goldfish brain and pituitary.
Characterization of cholecystokinin binding sites in goldfish brain and pituitary.
复制标题
金鱼大脑和垂体中胆囊收缩素结合位点的表征。
DOI：
10.1152/ajpregu.1996.271.1.r137
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Richard E. Peter
中科院分区：
文献类型：
--
作者：
B. A. Himick;S. Vigna;Richard E. Peter
测定了金鱼中枢神经系统（CNS）中胆囊收缩素（CCK）/胃泌素结合位点的特征和分布。在组织切片中发现125 I-硫酸化CCK八肽（125 I-CCK-8 s）的结合是可饱和的、可逆的、时间依赖性的，并且可被CCK/胃泌素样肽取代。饱和平衡结合的分析揭示了一个高亲和力结合位点（解离常数为0.706 +/- 0.188 nM），它也显示出对胃泌素-17 s和雨蛙肽的高亲和力。观察到非硫酸化形式的CCK-8和胃泌素-17的亲和力较低。这些结果表明，一个单一的原始CCK/胃泌素受体存在于金鱼中枢神经系统。CCK/胃泌素结合位点在金鱼脑和垂体中的分布揭示了端脑和视前下丘脑内的高密度，以及与脑摄食中心相关的下丘脑核团内的高密度。高密度的结合位点也定位在中脑被盖和视顶盖的中脑，面叶和迷走神经叶的后脑，垂体远侧部内。总之，这些发现支持了以前的研究表明，CCK/胃泌素样肽在鱼类摄食行为和垂体激素分泌的中枢调节中发挥作用。
The characterization and distribution of cholecystokinin (CCK)/gastrin binding sites were determined in the goldfish central nervous system (CNS). Binding of 125I-sulfated CCK octapeptide (125I-CCK-8s) in tissue sections was found to be saturable, reversible, time dependent, and displaceable by CCK/gastrin-like peptides. Analysis of saturable equilibrium binding revealed a high-affinity binding site (dissociation constant of 0.706 +/- 0.188 nM), which also displayed high affinity for gastrin-17s and caerulein. Lower affinities were observed for the nonsulfated forms of CCK-8 and gastrin-17. These findings suggest that a single primitive CCK/gastrin receptor exists in the goldfish CNS. The distribution of CCK/gastrin binding sites in the goldfish brain and pituitary revealed high densities within the telencephalon and preoptic hypothalamus, as well as within hypothalamic nuclei associated with the brain feeding center. High densities of binding sites were also localized within the midbrain tegmentum and optic tectum of the midbrain, the facial lobe and vagal lobe of the hindbrain, and within the pituitary pars distalis. Overall, these findings support previous studies that indicate that CCK/gastrin-like peptides play a role in the central regulation of feeding behavior and pituitary hormone secretion in fish.