Martin-Schild S, Zadina J E, Gerall A A, Vigh S, Kastin A J
VA Medical Center, New Orleans, LA 70146, USA.
Peptides. 1997;18(10):1641-9. doi: 10.1016/s0196-9781(97)00320-3.
Endomorphin-1 (Tyr-Pro-Trp-Phe-NH2) and endomorphin-2 (Tyr-Pro-Phe-Phe-NH2) are endogenous ligands that have greater affinity and selectivity for the mu-opiate receptor than any other known mammalian peptide. A polyclonal antiserum, screened for specificity to endomorphin-2 by immunodot-blot assay and preabsorption controls, was used for localization of this peptide. Immunocytochemistry performed on the brainstem, spinal cord, and sensory ganglia of rats by the avidin-biotin-peroxidase method revealed a continuous dense aggregation of endomorphin-2-like immunoreactive varicose fibers in the superficial laminae of the dorsal horn of the medulla and spinal cord. Immunoreactive fibers were detected in the dorsal root as well as within the dorsal root ganglia. The results suggest that endomorphin-2 is synthesized in primary sensory neurons in ganglia, transported to the superficial dorsal horn, and released near neurons expressing mu receptors. Its distribution appears to represent a functional unit likely to be associated with modulation of nociceptive stimuli.
内吗啡肽-1（酪氨酰-脯氨酰-色氨酰-苯丙氨酰胺）和内吗啡肽-2（酪氨酰-脯氨酰-苯丙氨酰-苯丙氨酰胺）是内源性配体，它们对μ-阿片受体的亲和力和选择性比任何其他已知的哺乳动物肽都要高。通过免疫斑点印迹分析和预吸收对照筛选出对内吗啡肽-2具有特异性的多克隆抗血清，用于该肽的定位。采用抗生物素蛋白-生物素-过氧化物酶法对大鼠脑干、脊髓和感觉神经节进行免疫细胞化学研究，结果显示在延髓和脊髓背角浅层中，内吗啡肽-2样免疫反应性曲张纤维呈连续密集聚集。在背根以及背根神经节内均检测到免疫反应性纤维。这些结果表明，内吗啡肽-2在神经节中的初级感觉神经元中合成，运输至背角浅层，并在表达μ受体的神经元附近释放。其分布似乎代表了一个可能与伤害性刺激调节相关的功能单位。
