Jiang W, Kreis M E, Eastwood C, Kirkup A J, Humphrey P P, Grundy D
Department of Biomedical Science, University of Sheffield, Sheffield, England.
Gastroenterology. 2000 Nov;119(5):1267-75. doi: 10.1053/gast.2000.19461.
BACKGROUND & AIMS: The mechanisms underlying brain stem activation during antigen challenge have not been resolved. Our aim was to characterize afferent nerve responses to intestinal anaphylaxis and determine the mediators involved in afferent activation.
Mesenteric afferent discharge was recorded electrophysiologically after intestinal anaphylaxis in anesthetized rats previously sensitized to chicken egg albumin (EA).
Mesenteric afferent nerve discharge increased approximately 1 minute after luminal antigen but not bovine serum albumin (P < 0.001, EA vs. bovine serum albumin). Subsequent administration of antigen had no effect, but systemic EA evoked a marked increase in afferent discharge (P < 0. 05). Afferent responses were unrelated to intestinal motor activity, and the response to luminal antigen was attenuated by luminal anesthetic (1% lidocaine). The 5-HT(3)-receptor antagonist alosetron (30 microg. kg(-1)) and the histamine H(1)-receptor antagonist pyrilamine (5 mg. kg(-1)) markedly attenuated the response to luminal antigen; pretreatment with doxantrazole attenuated responses to both luminal and systemic antigen.
5-HT(3) and histamine, released from mast cells after intestinal anaphylaxis, stimulate mesenteric afferents via 5-HT(3) and histamine H(1) receptors. Information on intestinal immune status is rapidly relayed to the central nervous system and may play a role in neural reflexes and behavioral responses following activation of the immune system.
抗原激发过程中脑干激活的潜在机制尚未明确。我们的目的是描述传入神经对肠道过敏反应的应答，并确定参与传入激活的介质。
在先前已对鸡卵白蛋白（EA）致敏的麻醉大鼠中，肠道过敏反应后通过电生理学记录肠系膜传入神经放电。
腔内给予抗原后约1分钟，肠系膜传入神经放电增加，但给予牛血清白蛋白后无此现象（P < 0.001，EA与牛血清白蛋白相比）。随后再次给予抗原无作用，但全身性给予EA可使传入放电显著增加（P < 0.05）。传入反应与肠道运动活性无关，腔内麻醉剂（1%利多卡因）可减弱对腔内抗原的反应。5-HT(3)受体拮抗剂阿洛司琼（30μg·kg⁻¹）和组胺H(1)受体拮抗剂吡苄明（5mg·kg⁻¹）可显著减弱对腔内抗原的反应；多沙唑嗪预处理可减弱对腔内和全身性抗原的反应。
肠道过敏反应后肥大细胞释放的5-HT(3)和组胺通过5-HT(3)和组胺H(1)受体刺激肠系膜传入神经。肠道免疫状态的信息迅速传递至中枢神经系统，可能在免疫系统激活后的神经反射和行为反应中起作用。
