[Porphyrins in renal calculi (review)]

We performed a review of the porphyrines content in a type of black, charcoal-like, renal calculi exhibiting infrared spectra (IRS) similar to those characteristic of "organic material" which has not yet been fully elucidate. Several other types of renal calculi, mainly those of small size, spontaneous passage renal stone, may also have diffuse or isolated dark charcoal components showing "organic material" IRS. After observing that haemoglobin has an "organic material" IRS, we studied, by a sensitive thin layer chromatography method, the presence of porphyrines in several types of dark or charcoal renal stones, since porphyrines are the physiological precursors of haemo group biosynthesis. We found two types of porphyrine content: coproporphyrin, in patients suffering from hepatopathy, and uroporphyrin and heptacarboxil-porphyrin in patients with some types of porphyria or with chronic renal failure.