Alpha-toxin, produced in large amounts by Clostridium perfringens type A strain, is phospholipase C(PLC) and is believed to be the major factor responsible for several biological damages of animals and humans. We attempted to know the expressions of drug metabolism related enzymes, cytochrome P450s(P450s) and membrane lipid peroxidation product, 4-hydroxy-2-nonenal(HNE) after injection of PLC or purified alpha-toxin in Sprague-Dawley rats.
The serum-biochemical value which is used as an indicator for major liver damages, activities of asparatate aminotransferase(AST) and alanine aminotransferase(ALT) after injection of PLC increased by 2-fold and 3-fold, respectively. Immunohistochemical staining for P450 1A1/2, 2B1/2, 2E1, 3A1 and 4A2/3 was performed in liver at various times after injection of PLC or alpha toxin. In all experimental groups, immunoreactivities of P450 2E1, 2B1/2, 1A1/2 and 4A2/3 were weak and the immunoreactivities of P450 2C11 were not detectable until 6hrs. Among them,P4503A1 showed strong immunoreactivity on pericentral area at 2hrs after PLC administration. Following a time course of 1∼24 hrs, HNE, a product of lipid peroxidation, was noted positive immunoreactivity on the peripheral area after PLC injection. In immunoblot analyses, the expressions of P450 2E1, 2B1/2, 1A1/2 and 4A2/3 slightly decreased while P450 2C11 significantly decreased until 6hrs. In contrast, HNE was significantly induced at 3.5hrs and increased expression of HNE persisted until 6hrs.
In conclusion, the increased expression of HNE, a well known toxic product of the membrane lipid, indicated that PLC showed drug metabolizing enzyme via suicidal inhibitory effects and functions. So, these data support a membrane damaging effect of enzymatic impairment in pathological conditions of the lipid peroxidation.
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