Richard M A, Serres F, Giravalli P, Noe C, Grob J J, Hesse S, Bonerandi J J, Jeanningros R
Service de Dermatologie, Hôpital Sainte Marguerite, Marseille.
Ann Dermatol Venereol. 1998 Mar;125(3):167-70.
Chronic idiopathic urticaria is known to have psychogenic component with a triggering or favoring effect. Different tests or evaluation scales have been unable to identify a specific psychological profile. Erythrocyte-specific membrane transport of tyrptophan (TRP), the main plasma precursor of cerebral serotonin synthesis, controls, by a erythrocyte-specific storage and release mechanism, circulating TRP homeostasis. Bioavailability of circulating TRP is a factor controlling serotonin synthesis in the brain. An evaluation of the rate of TRP transfer could be a biochemical approach to chronic urticaria more informative than psychological tests.
A kinetic study of L-TRP influx into circulating erythrocytes was conducted in 17 patients with chronic urticaria with no detectable cause and in 35 healthy controls. Blood samples were marked with 3H-TRP. Maximum L-TRP-specific influx (Vmax) was expressed in mumol/cell/min. The urticaria patients also underwent psychological testing to determine anxiety and depression scores using standardized scales (Hamilton).
Mean Vmax was not significantly difference between the two groups. Vmax values were quite similar in all the control subjects but showed wide dispersion in the urticaria group. Three subgroups were found in the urticaria patients depending on Vmax: those with Vmax equivalent in control levels (+2 SD), those with Vmax less then 2 SD (29% of the patients) and those with Vmax greater than 2 SD of control levels (23% of the patients). Thus more than 50% of the urticaria patients had perturbed erythrocyte-specific L-TRP influx. The anxiety and depression scores obtained from the psychological evaluation were not correlated with Vmax.
Erythrocyte-specific TRP membrane transport, evaluated by Vmax. Would not appear to be perturbed in chronic urticaria. Even though the urticaria patients could be divided into three groups according to their Vmax, the mean value was not significantly different from that in controls. These findings do not allow a conclusion concerning a perturbation of bioavailability of plasmatic TRP and any possible central serotoninergic dysfunction in chronic urticaria.
已知慢性特发性荨麻疹具有心理因素，具有触发或促进作用。不同的测试或评估量表无法识别特定的心理特征。色氨酸（TRP）是大脑血清素合成的主要血浆前体，其红细胞特异性膜转运通过红细胞特异性储存和释放机制控制循环中TRP的稳态。循环中TRP的生物利用度是控制大脑中血清素合成的一个因素。评估TRP转运速率可能是一种比心理测试更具信息量的慢性荨麻疹生化研究方法。
对17例无明显病因的慢性荨麻疹患者和35例健康对照者进行了L-TRP流入循环红细胞的动力学研究。血样用3H-TRP标记。最大L-TRP特异性流入量（Vmax）以μmol/细胞/分钟表示。荨麻疹患者还接受了心理测试，使用标准化量表（汉密尔顿量表）确定焦虑和抑郁评分。
两组的平均Vmax无显著差异。所有对照受试者的Vmax值相当相似，但荨麻疹组的Vmax值差异较大。根据Vmax，荨麻疹患者中发现了三个亚组：Vmax与对照水平相当（+2标准差）的患者、Vmax低于2标准差的患者（占患者的29%）和Vmax高于对照水平2标准差的患者（占患者的23%）。因此，超过50%的荨麻疹患者红细胞特异性L-TRP流入受到干扰。心理评估获得的焦虑和抑郁评分与Vmax无关。
通过Vmax评估的红细胞特异性TRP膜转运在慢性荨麻疹中似乎未受干扰。尽管荨麻疹患者可根据其Vmax分为三组，但其平均值与对照组无显著差异。这些发现无法得出关于慢性荨麻疹中血浆TRP生物利用度受干扰以及任何可能的中枢5-羟色胺能功能障碍的结论。
