The present work deals with the effect of
desferrioxamine (DF) on
hexachlorobenzene (
HCB)-induced
porphyria in female rats with the purpose of further investigation of the role of
iron in the development of this
porphyria. The results obtained show that the repeated injection of DF (three times a week: 100 mg/kg each i.m.) delayed and diminished remarkably the urinary excretion of precursors and
porphyrins as well as the accumulation of the latter in liver promoted by
HCB (1 g/kg daily given by stomach tube). This was probably due to attenuation by DF of the alterations produced by the fungicide in the two key
enzymes:
porphyrinogen carboxy-lyase (PCL) and delta-aminolaevulinate synthase (ALA-S). In fact, DF by reducing liver
iron levels produced a smaller decrease of the target
enzyme (PCL) and a concomitant smaller induction of ALA-S. DF alone did not modify any of these variables or the liver to
body weight ratio. DF added
at 10(-2) and 10(-3) M to the incubation media of ALA-S and PCL did not alter either of the enzymatic activities, whether in normal or
HCB-porphyric preparations. The results obtained show that DF improved the biochemical picture during
HCB porphyria. They suggest that
iron plays an indirect role in the decrease of PCL
enzyme, possibly at the
HCB metabolization step. A common
iron-involving mechanism for the production of
porphyria by different chlorinated compounds is suggested.