Kalliomäki Maija-Liisa, Pertovaara Antti, Brandt Annika, Wei Hong, Pietilä Pirjo, Kalmari Jaakko, Xu Mei, Kalso Eija, Panula Pertti
Department of Biology, Abo Akademi University, Biocity Artillerigatan 6A, 20520 Turku, SF, Finland.
Neuropharmacology. 2004 Mar;46(3):412-24. doi: 10.1016/j.neuropharm.2003.09.021.
Prolactin-releasing peptide (PrRP) and neuropeptide FF (NPFF) are RF-amide peptides expressed in brain areas involved in pain modulation. NPFF displays multiple effects on acute, inflammatory and neuropathic pain. The potential role of PrRP in pain was addressed by intrathecal and intracerebral injections of PrRP on pain-related responses in both neuropathic and normal rats. Particularly in the dorsal medulla, PrRP produced significant antinociception in normal rats and an antiallodynic effect in neuropathic rats. To understand the basis of PrRP-induced pain modulation, distributions of PrRP, PrRP receptor, and NPFF were compared in the rat central nervous system. PrRP and NPFF mRNA were expressed in different parts of the nucleus of the solitary tract. In the medulla, PrRP receptor mRNA expression was abundant only in area postrema. Of the peptides studied, only NPFF mRNA was found in the dorsal horn of the spinal cord and spinal nucleus of the trigeminal nerve. PrRP-immunoreactivity corresponded to the mRNA distribution. Even if the neuronal groups producing NPFF and PrRP were distinct, the fiber networks immunoreactive for PrRP and NPFF overlapped. The results show that PrRP modulates nociception due to supraspinal rather than spinal action, and that its antinociceptive mechanism differs from that previously characterized for NPFF.
催乳素释放肽（PrRP）和神经肽FF（NPFF）是在参与疼痛调节的脑区表达的RF酰胺肽。NPFF对急性、炎症性和神经性疼痛具有多种作用。通过鞘内和脑内注射PrRP来研究其在神经性和正常大鼠疼痛相关反应中的作用，以探讨PrRP在疼痛中的潜在作用。特别是在延髓背侧，PrRP在正常大鼠中产生显著的镇痛作用，在神经性大鼠中产生抗痛觉过敏作用。为了理解PrRP诱导疼痛调节的基础，比较了PrRP、PrRP受体和NPFF在大鼠中枢神经系统中的分布。PrRP和NPFF mRNA在孤束核的不同部位表达。在延髓中，PrRP受体mRNA仅在最后区大量表达。在所研究的肽中，仅在脊髓背角和三叉神经脊束核中发现NPFF mRNA。PrRP免疫反应性与mRNA分布相对应。即使产生NPFF和PrRP的神经元群不同，但PrRP和NPFF的免疫反应性纤维网络相互重叠。结果表明，PrRP通过脊髓上而非脊髓作用来调节伤害感受，并且其镇痛机制与先前描述的NPFF不同。
