Moody T W, Getz R, O'Donohue T L, Rosenstein J M
Department of Biochemistry, George Washington University School of Medicine and Health Sciences, Washington, D.C. 20037.
Ann N Y Acad Sci. 1988;547:114-30. doi: 10.1111/j.1749-6632.1988.tb23880.x.
BN-like peptides and receptors are present in discrete areas of the mammalian brain. By radioimmunoassay, endogenous BN/GRP, neuromedin B, and ranatensin-like peptides are present in the rat brain. High-to-moderate concentrations of BN/GRP are present in the rat hypothalamus and thalamus, whereas moderate-to-high densities of neuromedin B and ranatensin-like peptides are present in the olfactory bulb and hippocampus, as well as in the hypothalamus and thalamus. While the distribution of neuromedin B and ranatensin-like peptides appears similar, it is distinct from that of BN/GRP. When released from CNS neurons, these peptides may interact with receptors for BN-like peptides. BN, GRP, ranatensin, and neuromedin B inhibit specific [125I-Tyr4]BN binding with high affinity. By use of in vitro autoradiographic techniques to detect binding of [125I-Tyr4]BN to receptors for BN-like peptides, high grain densities were found in the olfactory bulb and tubercle, the nucleus accumbens, the suprachiasmatic and paraventricular nucleus of the hypothalamus, the central medial and paraventricular thalamic nuclei, the hippocampus, the dentate gyrus, and the amygdala of the rat brain. Some of these receptors may be biologically active and mediate the biological effects of BN-like peptides. For example, when BN is directly injected into the nucleus accumbens, pronounced grooming results and the effects caused by BN are reversed by spantide and [D-Phe12]BN. Thus, the putative BN receptor antagonists may serve as useful agents to investigate the biological significance of BN-like peptides in the CNS.
类BN肽和受体存在于哺乳动物脑的特定区域。通过放射免疫测定法，大鼠脑中存在内源性BN/GRP、神经降压素B和蛙皮素样肽。大鼠下丘脑和丘脑存在高至中等浓度的BN/GRP，而嗅球、海马以及下丘脑和丘脑存在中等至高浓度的神经降压素B和蛙皮素样肽。虽然神经降压素B和蛙皮素样肽的分布似乎相似，但与BN/GRP的分布不同。当这些肽从中枢神经系统神经元释放时，它们可能与类BN肽的受体相互作用。BN、GRP、蛙皮素和神经降压素B以高亲和力抑制特异性[125I-Tyr4]BN结合。通过使用体外放射自显影技术检测[125I-Tyr4]BN与类BN肽受体的结合，在大鼠脑的嗅球和结节、伏隔核、下丘脑视交叉上核和室旁核、丘脑中央内侧核和室旁核、海马、齿状回和杏仁核中发现了高颗粒密度。其中一些受体可能具有生物活性并介导类BN肽的生物学效应。例如，当将BN直接注射到伏隔核中时，会产生明显的梳理行为，并且BN引起的效应可被spantide和[D-Phe12]BN逆转。因此，推定的BN受体拮抗剂可能是研究类BN肽在中枢神经系统中生物学意义的有用试剂。
