Rcg. Carneiro et Rj. Reiter, DELTA-AMINOLEVULINIC ACID-INDUCED LIPID-PEROXIDATION IN RAT-KIDNEY AND LIVER IS ATTENUATED BY MELATONIN - AN IN-VITRO AND IN-VIVO STUDY, Journal of pineal research, 24(3), 1998, pp. 131-136
Acute intermittent porphyria (AIP) is a genetically inherited disease
characterized by a partial block in liver heme biosynthesis and by inc
reased urinary excretion of the delta-aminolevulinic acid (ALA). Recen
tly, it has been proposed that the toxic effects of ALA are related to
the generation of free radicals. In the present study the in vitro an
d in vivo effect of melatonin, a recently described antioxidative agen
t, on ALA-induced lipid peroxidation in rat liver and kidney was deter
mined. The concentration of malonaldehyde (MDA) and 4-hydroxyalkenals
(4-HDA) was assayed as an index of induced membrane oxidative damage.
In vitro melatonin protected, in a concentration-dependent manner, aga
inst ALA-induced lipid peroxidation in liver and kidney homogenates. I
n in vivo experiments as well, it was demonstrated that ALA (40 mg/kg)
-induced lipid peroxidation in liver and kidney was reduced by acute m
elatonin (10 mg/kg) treatment. The results support the involvement of
free radicals in ALA toxicity and show that in vitro and in vivo melat
onin confers protection against this toxicity, likely due to the antio
xidative capability of the indole.