Accumulation of protoporphyrin-IX in rat Leydig cells following induction by 5-aminolevulinic acid and tramadol.
OBJECTIVE
This study aimed to monitor the accumulation of endogenous protoporphyrin-IX (PpIX) in rat Leydig cells (R(2)C) under the effect of 5-aminolevulinic acid (ALA) and various concentrations of tramadol, an analgesic drug.


BACKGROUND
Pain during photodynamic treatment with ALA is one of the adverse effects of this new treatment to eradicate tumor cells. ALA is utilized in photodynamic diagnosis and therapy (PDT) as a compound capable of augmenting the intracellular pool of PpIX, which exhibits properties of a photosensitizer.


METHODS
Cellular content of PpIX was determined following incubation of the cells for 1 and 2 h in culture medium that contained ALA and different concentrations of tramadol. The amount of PpIX was determined using fluorescent technique under a confocal microscope (laser wavelength 458 nm and filter LP 585 nm), and evaluated using CytFlu 1.2 software.


RESULTS
After 1 h of incubation, no significant alterations were noted in the cellular PpIX concentration. However, 2 h of incubation resulted in a significant increase (p < 0.05) in PpIX fluorescence inside the cells, when the medium contained ALA and tramadol in concentrations ranging from 1-2 mg/1 mL.


CONCLUSIONS
The results suggested that in R(2)C cells, exogenous ALA and tramadol induced protoporphyrin accumulation. This information is useful for two reasons. First, it may help to diminish pain after ALA-PDT treatment; and second, it allows the use of lower concentrations of ALA during therapy.
D000622:Aminolevulinic Acid / Q000627:therapeutic use*; D000701:Analgesics, Opioid / Q000008:administration & dosage*; D000818:Animals; D007984:Leydig Cell Tumor / Q000378:metabolism*; D008297:Male; D018613:Microscopy, Confocal; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D011524:Protoporphyrins / Q000378:metabolism*; D051381:Rats; D014147:Tramadol / Q000008:administration & dosage*; D014407:Tumor Cells, Cultured / Q000528:radiation effects
D000701:Analgesics, Opioid; D017319:Photosensitizing Agents; D011524:Protoporphyrins; D014147:Tramadol; C011539:protoporphyrinogen; D000622:Aminolevulinic Acid