[Effect of the thioctamide in relation to the hexachlorobenzene action]

Chronic administration of Hexachlorobenzene, with or without the simultaneous administration of Tioctamide was assayed. Hexachlorobenzene alone produced the characteristic porphyria, detected through an increase of the urinary excretion and the hepatic accumulation of porphyrins, as well as by a decrease of the Uroporphyrinogen decarboxylase activity. The content of hepatic conjugated dienes did not change while those of malondialdehyde increased, although without reaching levels of statistical significance. These results would indicate the occurrence of an light lipid peroxidation process. The Thioctamide (25 mg/kg body weight) produced more noxious effects than protective ones, which were detected by a high level of Glutamate piruvate transaminase activity and a decrease of the hepatic Uroporphyrinogen decarboxylase activity, at its first step of decarboxylation. These results might indicate that: 1) high doses of Thioctamide decreases Uroporphyrinogen decarboxylase activity, masking its possible protective effect from Hexachlorobenzene's action through free radicals production and, 2) Uroporphyrinogen decarboxylase is a more sensitive parameter than conjugated dienes or malondialdehyde levels to assay the free radicals in vivo Hexachlorobenzene production. In any case, the Thioctamide assayed in lower and non toxic doses, perhaps might protect against Hexachlorobenzene's action through its free radical scavenger ability.