Effect of lead on ALA-D activity, metallothionein levels, and lipid peroxidation in blood, kidney, and liver of the toadfish Halobatrachus didactylus

摘要

The effects of lead (Pb) on ALA-D activity, metallothionein (MT) levels, and lipid peroxidation in liver, kidney, and blood of the toadlish Halobatrachus didactylus were investigated. A time-course experiment was performed with sampling on days 0, 2, 5, and 7 following intraperitoneal Pb injection. This indicated a rank order for lead concentration of kidney > liver > blood in fish exposed to Pb. No significant variation of ALA-D activity was observed in liver and kidney while in blood, a slight decrease of ALA-D activity was found but this was not attributed to acute metal stress. Hepatic and renal MT levels were both affected in different ways by metal uptake. The progressive decrease of MDA concentration in the liver and the lack of a clear induction in kidney suggested the hypothesis that Pb is not a good inductor of lipid peroxidation. The histologicaland histochemical results demonstrated degenerative effects of lead accumulation on the tissues and the activation of lysosomal responses to induced stress.