Ambar I, Kloog Y, Kochva E, Wollberg Z, Bdolah A, Oron U, Sokolovsky M
Department of Biochemistry, George S. Wise Faculty of Life Sciences, Tel Aviv University, Israel.
Biochem Biophys Res Commun. 1988 Dec 30;157(3):1104-10. doi: 10.1016/s0006-291x(88)80987-2.
We have recently shown that the rat atrium and brain contain specific high affinity receptors for the novel snake vasoconstrictor peptide sarafotoxin-b (SRTXb), and demonstrated toxin-induced phosphoinositide hydrolysis. Here we report on the characteristics of 125I-SRTXb receptors and their regional distribution in rat brain. 125I-SRTX receptors in the rat brain bind the toxin rapidly and with high affinity. The binding was not inhibited by ligands of known neurotransmitter receptor and ion channels. 125I-SRTX receptors have a distinctive regional distribution. The highest densities were observed in the cerebellum, thalamus and hypothalamus (850, 550 and 450 fmol/mg protein, respectively) and the lowest densities in the caudate and cerebral cortex (82 and 62 fmol/mg protein, respectively). Taken together our results suggest that mammalian brains contain a hitherto undetected neuroreceptor that may operate in neurotransmission with a "SRTX-like" brain peptide, similar to the SRTX homologous vasoconstrictor peptide of the mammalian endothelium endothelin.
我们最近发现，大鼠心房和大脑中含有新型蛇血管收缩肽沙拉毒素 - b（SRTXb）的特异性高亲和力受体，并证实了毒素诱导的磷酸肌醇水解。在此，我们报告125I - SRTXb受体的特性及其在大鼠脑中的区域分布。大鼠脑中的125I - SRTX受体能快速且高亲和力地结合该毒素。已知神经递质受体和离子通道的配体不会抑制这种结合。125I - SRTX受体具有独特的区域分布。在小脑、丘脑和下丘脑观察到最高密度（分别为850、550和450 fmol/mg蛋白质），而在尾状核和大脑皮层密度最低（分别为82和62 fmol/mg蛋白质）。综合我们的结果表明，哺乳动物大脑中含有一种迄今未被发现的神经受体，它可能与一种“类似SRTX”的脑肽一起参与神经传递，类似于哺乳动物内皮细胞内皮素的SRTX同源血管收缩肽。
