Effect of 5-aminolevulinic acid (ALA) doses and oestrogen/progesterone on protoporphyrin IX (PpIX) accumulation in human endometrial epithelial cells

Endometriosis represents one of the most frequent causes of restricted fecundity. Despite the progress in medicine, appropriate diagnosis and treatment pose significant problems. The aim of this study was to evaluate ALA-induced PpIX fluorescence of normal endometrial epithelial cells for the diagnosis of endometriosis. PpIX-fluorescence was measured after stimulation with estradiol-17 beta (E2) or with estradiol-17 beta (E2) and progesterone (P) and after incubation with ALA under a confocal microscope. The epithelial cells showed a significantly higher fluorescence of PpIX in the course of 24 and 48h incubation with hormones, than the cells without stimulation. After 72h, a significant decrease in cellular PpIX concentration was noted. The results suggested that E2 and P were required to convert ALA to PpIX in epithelial cells and increased PpIX concentration in a time-dependent fashion.