Selmer I S, Schindler M, Humphrey P P, Emson P C
Department of Neurobiology, The Babraham Institute, Babraham Hall, CB2 4AT, Cambridge, UK.
Neuroscience. 2000;98(3):523-33. doi: 10.1016/s0306-4522(00)00147-0.
The biological actions of the neuromodulator somatostatin are mediated through a family of G-protein-coupled receptors, of which five members, sst(1-5), have been identified. Although the messenger RNA distribution of the sst(4) receptor has been reported, no information about the distribution of the receptor protein in the central nervous system is available. We have therefore raised a polyclonal peptide antibody against a rat carboxy-terminal sst(4) peptide. The selectivity of the affinity-purified antibody was demonstrated by western blotting of membrane proteins isolated from Chinese hamster ovary-K1 cells expressing the recombinant sst(4) receptor and from the rat hippocampus. This resulted in both cases in the identification of a single band of approximately 42,000 mol. wt. Furthermore, the sst(4) receptor antibody selectively labelled Chinese hamster ovary-K1 cells expressing the recombinant sst(4) receptor in immunocytochemistry. No cross-reactivity was observed with other recombinant somatostatin receptors. Immunohistochemistry on adult rat brain sections showed the sst(4) receptor to have a widespread distribution. This included labelling of cell bodies as well as processes in the cerebral cortex, hippocampus and several nuclei in the brainstem. All signals were absent following antibody preabsorption with the synthetic sst(4) peptide. This study provides the first detailed analysis of the distribution of sst(4) receptor protein in the rat brain.
神经调质生长抑素的生物学作用是通过一类G蛋白偶联受体介导的，已鉴定出其中五个成员，即sst(1-5)。虽然已报道了sst(4)受体的信使核糖核酸分布，但尚无关于该受体蛋白在中枢神经系统中分布的信息。因此，我们制备了一种针对大鼠羧基末端sst(4)肽的多克隆肽抗体。通过对从表达重组sst(4)受体的中国仓鼠卵巢-K1细胞和大鼠海马体中分离的膜蛋白进行蛋白质印迹，证明了亲和纯化抗体的选择性。在这两种情况下，均鉴定出一条分子量约为42,000道尔顿的单一条带。此外，在免疫细胞化学中，sst(4)受体抗体选择性地标记了表达重组sst(4)受体的中国仓鼠卵巢-K1细胞。未观察到与其他重组生长抑素受体的交叉反应。对成年大鼠脑切片进行免疫组织化学分析显示，sst(4)受体分布广泛。这包括在大脑皮层、海马体和脑干中的几个核团中标记细胞体以及神经突起。用合成的sst(4)肽预吸收抗体后，所有信号均消失。本研究首次对大鼠脑中sst(4)受体蛋白的分布进行了详细分析。
