Inhibition of scratching behaviour caused by contact dermatitis in histidine decarboxylase gene knockout mice
Inhibition of scratching behaviour caused by contact dermatitis in histidine decarboxylase gene knockout mice
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DOI：
10.1111/j.0906-6705.2005.00247.x
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发表时间：
2005-03-01
影响因子：
3.6
通讯作者：
Ohtsu, H
中科院分区：
文献类型：
--
作者：
Seike, M;Ikeda, M;Ohtsu, H
一个专门负责瘙痒的神经元系统由初级传入神经元和脊髓丘脑投射神经元组成。组胺被认为是传递瘙痒感觉的主要介质之一。然而，组胺在特应性皮炎和慢性湿疹的抓挠行为和感觉传递中的作用几乎没有可用的信息。在本研究中，组胺在慢性湿疹模型中的抓挠行为和感觉的神经传导的作用进行了研究，通过使用缺乏组胺的L-组氨酸脱羧酶（HDC）基因敲除小鼠。通过在HDC（+/ +）和HDC（-/-）小鼠的后爪上每天应用二苯基环丙烯酮（DCP）诱导慢性接触性皮炎，持续2个月。对两只小鼠进行抓挠行为观察和热板试验。在皮肤和脊髓组织中进行组织学研究。组织学检查显示HDC（+/+）和HDC（-/-）小鼠在皮肤组织中显示相似程度的炎性细胞浸润、增生的表皮和新的神经突起扩散。仅在HDC（+/+）小鼠中诱导了痉挛行为，而在HDC（-/-）小鼠中几乎没有观察到。在HDC（+/+）小鼠中，反复应用DCP后脊髓背角I层中c-Fos的表达特异性上调。小鼠慢性接触性皮炎的痉挛行为主要由组胺介导。慢性接触性皮炎模型的感觉传入通路可能通过脊髓背角的第一层与中枢神经系统联系。
A neuronal system dedicated to itch consists of primary afferent and spinothalamic projection neurons. Histamine is thought to be one of the main mediators for the transmission of itch sensation. However, there are little available information on the role of histamine in scratching behaviour and sensory transmission of atopic dermatitis and chronic eczema. In the present study, the role of histamine in scratching behaviour and neural conduction of sensation in the chronic eczema model was investigated by using l-histidine decarboxylase ( HDC) gene knockout mice lacking histamine. The chronic contact dermatitis was induced with daily application of diphenylcyclopropenone ( DCP) on a hind paw of HDC (+/ +) and HDC (-/-) mice for 2 months. The observation of scratching behaviour and the hot-plate test were performed in both mice. Histological studies were performed in the skin and spinal cord tissues. Histological examination revealed that both HDC ( +/+) and HDC (-/-) mice displayed the similar extent of inflammatory cell infiltration, hyperplastic epidermis and newly spreading of neuronal processes in the skin tissue. Scratching behaviour was exclusively induced in HDC (+/+) mice, whereas it was barely observed in HDC (-/-) mice. The expression of c-Fos was specifically upregulated in HDC (+/+) mice in lamina I of the spinal dorsal horn following repeated DCP application. Scratching behaviour in chronic contact dermatitis in mice was thought mainly mediated with histamine. The afferent pathway of sensation in chronic contact dermatitis model may connect with the central nervous system through lamina I of the spinal dorsal horn.