Saria A, Javorsky F, Humpel C, Gamse R
Department of Psychiatry, University of Innsbruck Medical School, Austria.
Neuroreport. 1990 Oct;1(2):104-6. doi: 10.1097/00001756-199010000-00005.
5-HT3 receptors may be present on primary afferent neurons containing substance P (SP), neurokinin A (NKA) or calcitonin gene-related peptide (CGRP). We investigated the release of SP-, NKA- and CGRP-immunoreactivities (IR) from rat spinal cord slices. Thirty mM potassium chloride caused an increased outflow of all three peptides, i.e. 140-190% of spontaneous release. This release was slightly enhanced in the presence of 3 x 10(-5) M 5-hydroxytryptamine (5-HT). In contrast, a significant inhibition of potassium-evoked, but not of basal NKA-IR and CGRP-IR release was observed when 10(-7) M BRL 43694 or ICS 205-930, two specific 5-HT3 receptor antagonists, were superfused together with 5-HT. In conclusion, 5-HT may facilitate the evoked release of peptides from central terminals of primary sensory neurons via 5-HT3 receptors.
5-羟色胺3（5-HT3）受体可能存在于含有P物质（SP）、神经激肽A（NKA）或降钙素基因相关肽（CGRP）的初级传入神经元上。我们研究了大鼠脊髓切片中SP、NKA和CGRP免疫反应性（IR）的释放情况。30 mM氯化钾导致所有这三种肽的流出增加，即自发释放量的140 - 190%。在存在3×10⁻⁵ M 5-羟色胺（5-HT）的情况下，这种释放略有增强。相比之下，当10⁻⁷ M BRL 43694或ICS 205 - 930（两种特异性5-HT3受体拮抗剂）与5-HT一起灌流时，观察到钾离子诱发的NKA-IR和CGRP-IR释放受到显著抑制，但基础释放未受影响。总之，5-HT可能通过5-HT3受体促进初级感觉神经元中枢终末的肽释放。
