Santucci B, Cannistraci C, Cristaudo A, Camera E, Picardo M
San Gallicano Dermatological Institute, Rome, Italy.
Contact Dermatitis. 1999 Jan;40(1):8-13. doi: 10.1111/j.1600-0536.1999.tb05969.x.
The aim of this paper was to evaluate whether methylmercury chloride (MeHgCl) aq., when patch tested in a group of thimerosal-positive subjects reacting to ethylmercury chloride (EtHgCl), might be a reliable model for the better understanding of interactions between alkylmercury compounds and the skin. 19 out of 21 consecutive patients who previously had given positive patch-test reactions to both ethylmercury chloride 0.0165% eth.(EtHgCl, 0.615 mM) and MeHgCl 0.031% aq.(1.23 mM), and negative reactions to thiosalicylic acid 0.05% (3.24 mM) aq./eth. 50/50, were repatch tested to 8 microl of MeHgCl 0.031% aq. and to 8 microl of aq. solutions containing MeHgCl mixed with cysteine, glutathione, ZnSO4, MgSO4, MnSO4, ZnCl2, MgCl2 and MnCl2, respectively. The results showed that cysteine, glutathione and Zn(II) salts were able to abolish the positive reactions, demonstrating the rôle played by both thiol groups and Zn(II) itself. Patch tests concomitantly carried out in 16 out of 19 patients to 8 microl of aqueous MeHgCl and to 8 microl of aqueous solutions containing MeHgCl and MeHgCl mixed to fragment 56-61 of metallothionein I (MT I), MT I and MT II-Zn, respectively, revealed that all the MTs tested were able to reduce or to inhibit the reactions, demonstrating the effect of the thiol groups. Due to the close chemical similarities to EtHgCl and to its water solubility, MeHgCl seems to be a suitable model for evaluating the reactivity of alkylmercury compounds in the skin. We speculate that both EtHg- and MeHg-derivatives are xenobiotics with similar reactivity. However, the lack of clinical relevance of the reactions to both alkyl compounds lead us to conclude that, since environmental exposure does not seem to play a pivotal rôle, they probably have mostly to do with compounds included in in the standard series, and are elicited by reduced function of physiological SH chelators.
本文的目的是评估当在一组对氯化乙基汞（EtHgCl）产生反应的硫柳汞阳性受试者中进行斑贴试验时，氯化甲基汞（MeHgCl）水溶液是否可能是一个可靠的模型，以更好地理解烷基汞化合物与皮肤之间的相互作用。在21例连续患者中，有19例先前对0.0165%乙醇（eth.）的氯化乙基汞（EtHgCl，0.615 mM）和0.031%水溶液（1.23 mM）的MeHgCl斑贴试验呈阳性反应，而对0.05%（3.24 mM）水溶液/乙醇50/50的硫代水杨酸斑贴试验呈阴性反应，对8微升0.031%水溶液的MeHgCl以及分别与半胱氨酸、谷胱甘肽、硫酸锌、硫酸镁、硫酸锰、氯化锌、氯化镁和氯化锰混合的含MeHgCl的水溶液进行重新斑贴试验。结果表明，半胱氨酸、谷胱甘肽和锌（II）盐能够消除阳性反应，证明了巯基和锌（II）本身所起的作用。在19例患者中的16例中，同时对8微升的MeHgCl水溶液以及分别与金属硫蛋白I（MT I）的56 - 61片段、MT I和MT II - Zn混合的含MeHgCl的水溶液进行斑贴试验，结果显示所有测试的MT都能够减轻或抑制反应，证明了巯基的作用。由于与EtHgCl在化学性质上非常相似且具有水溶性，MeHgCl似乎是评估烷基汞化合物在皮肤中反应性的合适模型。我们推测EtHg - 和MeHg - 衍生物都是具有相似反应性的外源性物质。然而，对这两种烷基化合物反应缺乏临床相关性使我们得出结论，由于环境暴露似乎并不起关键作用，它们可能主要与标准系列中的化合物有关，并且是由生理性SH螯合剂功能降低引起的。
