Fritsch C, Homey B, Stahl W, Lehmann P, Ruzicka T, Sies H
Institute of Physiological Chemistry, Heinrich-Heine-University, Düsseldorf, Germany.
Photochem Photobiol. 1998 Aug;68(2):218-21.
Topically applied delta-aminolevulinic acid is used efficiently for the treatment of solar keratoses by photodynamic therapy. Recent animal studies suggest that porphyrin sensitization of epithelial tissue is improved by using esters rather than free delta-aminolevulinic acid. The present study examines porphyrin metabolite formation after topical application of delta-aminolevulinic acid or delta-amino-levulinic acid methylester in human solar keratoses versus adjacent normal skin. Level of total porphyrins, porphyrin metabolites and protein were measured in skin samples excised after 1 and 6 h. Higher levels of porphyrins were observed in solar keratoses than in normal skin with both substances. Maximum porphyrin levels were present in solar keratoses treated with delta-aminolevulinic acid for 6 h. However, the ratio of porphyrins in solar keratoses versus adjacent normal skin was higher with delta-aminolevulinic acid methylester. The pattern of porphyrins showed no significant difference between normal and afflicted skin, protoporphyrin being predominant. The results suggest that application of free delta-aminolevulinic acid may be more effective in sensitizing solar keratoses. However, treatment with delta-aminolevulinic acid methylester leads to a preferential enrichment of porphyrins within lesional skin.
局部应用δ-氨基乙酰丙酸通过光动力疗法可有效治疗日光性角化病。最近的动物研究表明，使用酯类而非游离的δ-氨基乙酰丙酸可改善上皮组织的卟啉致敏作用。本研究检测了在人类日光性角化病及相邻正常皮肤局部应用δ-氨基乙酰丙酸或δ-氨基乙酰丙酸甲酯后卟啉代谢产物的形成情况。在1小时和6小时后切除的皮肤样本中测量总卟啉、卟啉代谢产物和蛋白质的水平。两种物质在日光性角化病中均观察到比正常皮肤中更高的卟啉水平。用δ-氨基乙酰丙酸处理6小时的日光性角化病中存在最大卟啉水平。然而，δ-氨基乙酰丙酸甲酯处理的日光性角化病与相邻正常皮肤的卟啉比例更高。正常皮肤和患病皮肤之间的卟啉模式没有显著差异，原卟啉占主导。结果表明，应用游离的δ-氨基乙酰丙酸可能在日光性角化病致敏方面更有效。然而，用δ-氨基乙酰丙酸甲酯治疗会导致病变皮肤内卟啉的优先富集。
