Krogstad A L, Lönnroth P, Larson G, Wallin B G
Department of Dermatology, Sahlgren University Hospital, S-41345 Göteborg, Sweden.
Br J Dermatol. 1998 Sep;139(3):403-9. doi: 10.1046/j.1365-2133.1998.02402.x.
Psoriatic plaques contain an increased number of mast cells. Both the histamine concentration and release are increased in lesional skin but the underlying mechanisms are unclear. One hypothesis is that neuropeptides transmitted from thin sensory cutaneous nerves continuously stimulate mast cell release of histamine. The aim of this study was to test this hypothesis by examining if topical anaesthesia of these nerves inhibits histamine release in psoriatic skin. The concentration of histamine was measured in microdialysates obtained from lesional and non-lesional skin before and during topical anaesthesia. Concomitantly skin blood flow was measured with scanning laser Doppler (perfusion) and/or 133Xe clearance (flow) techniques in the microdialysis area. The histamine concentrations (mean +/- SEM) were 34 +/- 4 (n = 21), 14 +/- 1.5 (n = 18) (P < 0. 001) and 2.8 +/- 1 nmol/L (n = 10) in lesional and non-lesional skin and plasma, respectively. After anaesthesia of the microdialysis areas the histamine concentration in psoriatic skin increased to 44 +/- 4 nmol/L (n = 19, P < 0.05), but remained unaltered in uninvolved skin. In anaesthetized lesional skin the perfusion decreased from 3.7 +/- 0.2 to 2.5 +/- 0.3 V and blood flow decreased from 14 +/- 5 to 9 +/- 1 mL/min per 100 g (P < 0.001, n = 10). The calculated release of dermal histamine in involved skin (198 +/- 30 pmol/min per 100 g, n = 10) remained unchanged after local anaesthesia. The results indicate that neurogenic activation of mast cells is of minor importance for continuous histamine release in psoriatic skin and that the vasodilatation in the psoriatic plaque is not mediated by histamine.
银屑病斑块中肥大细胞数量增加。皮损处皮肤中组胺浓度及释放量均升高，但其潜在机制尚不清楚。一种假说认为，来自皮肤细感觉神经的神经肽持续刺激肥大细胞释放组胺。本研究的目的是通过检查对这些神经进行局部麻醉是否能抑制银屑病皮肤中组胺的释放来验证这一假说。在局部麻醉前和麻醉期间，测量从皮损和非皮损皮肤获得的微透析液中组胺的浓度。同时，在微透析区域用扫描激光多普勒（灌注）和/或133Xe清除（流量）技术测量皮肤血流量。皮损皮肤、非皮损皮肤和血浆中的组胺浓度（平均值±标准误）分别为34±4（n = 21）、14±1.5（n = 18）（P < 0.001）和2.8±1 nmol/L（n = 10）。对微透析区域进行麻醉后，银屑病皮肤中的组胺浓度升至44±4 nmol/L（n = 19，P < 0.05），但未受累皮肤中的组胺浓度保持不变。在麻醉的皮损皮肤中，灌注从3.7±0.2降至2.5±0.3 V，血流量从每100 g 14±5降至9±1 mL/min（P < 0.001，n = 10）。局部麻醉后，受累皮肤中计算得出的真皮组胺释放量（每100 g 198±30 pmol/min，n = 10）保持不变。结果表明，肥大细胞的神经源性激活对银屑病皮肤中组胺的持续释放作用较小，且银屑病斑块中的血管舒张不是由组胺介导的。
