Photoacoustic spectroscopy applied to the study of protoporphyrin IX induced in mice

We used Photoacoustic Spectroscopy (PAS) to study protoporphyrin IX (PpIX) in mice skin induced from delta -aminolevulinic acid (ALA) administrated by intraperitoneal route to CD 1 female mice. From obtained PAS spectra and b y using the Phase-Resolved Method we estimated that PpIX: in skin was prefe rentially concentrated near to the inner side of the basal membrane. It was also obtained the total attenuation coefficient (mu (t)) Of the mouse skin as a function of wavelength. The obtained mu (t) values, in particular at 630 nm agree with the literature values for similar samples. Also it was es timated in a first approximation the degradation time of PpIX when is irrad iated at its maximum optical absorption wavelength.