He D, Behar S, Roberts J E, Lim H W
Dermatology Service, Veterans Affairs Medical Center, New York, NY, USA.
Photodermatol Photoimmunol Photomed. 1996 Oct;12(5):194-9. doi: 10.1111/j.1600-0781.1996.tb00199.x.
The effects of L-cysteine (LC) and N-acetylcysteine (NAC) on porphyrin accumulation in a human dermal microvascular endothelial cell line (HMEC-1) and a human epidermoid carcinoma cell line (A431) loaded with 5-aminolevulinic acid (ALA) and exposed to ultraviolet A (UVA) and blue light radiation were determined. Porphyrin accumulation was decreased in the presence of 0.1-7.5 mM LC (24.8%-31.4% suppression in HMEC-1 cell; 35.8%-48.9% suppression in A431 cells), and in the presence of 0.1-10.0 mM NAC (30.9%-58.0% suppression in HMEC-1 cells; 8.5%-45.3% in A431 cells). The suppression occurred in a LC or NAC dose-dependent fashion. The above was associated with partial reversal of suppression of ferrochelatase (FeC) activity in HMEC-1 cells and in A431 cells. As compared to FeC activity in cells treated with ALA and irradiation, enzyme activity was higher (by 31.9%-62.1%) in the presence of LC (1.0 mM or 5.0 mM) and in the presence of NAC (1.0 mM or 5.0 mM). These data indicate that LC and NAC have protective effects on porphyrin- and irradiation-induced diminution of FeC activity in HMEC-1 cells and A341 cells in vitro.
测定了L-半胱氨酸（LC）和N-乙酰半胱氨酸（NAC）对加载5-氨基乙酰丙酸（ALA）并暴露于紫外线A（UVA）和蓝光辐射的人真皮微血管内皮细胞系（HMEC-1）和人表皮样癌细胞系（A431）中卟啉积累的影响。在存在0.1 - 7.5 mM LC的情况下（HMEC-1细胞中抑制24.8% - 31.4%；A431细胞中抑制35.8% - 48.9%）以及在存在0.1 - 10.0 mM NAC的情况下（HMEC-1细胞中抑制30.9% - 58.0%；A431细胞中抑制8.5% - 45.3%），卟啉积累减少。这种抑制以LC或NAC剂量依赖性方式发生。上述情况与HMEC-1细胞和A431细胞中铁螯合酶（FeC）活性抑制的部分逆转相关。与用ALA处理并照射的细胞中的FeC活性相比，在存在LC（1.0 mM或5.0 mM）和存在NAC（1.0 mM或5.0 mM）的情况下，酶活性更高（高31.9% - 62.1%）。这些数据表明，LC和NAC对体外HMEC-1细胞和A341细胞中卟啉和辐射诱导的FeC活性降低具有保护作用。
