ABSTRACT
The effects of mirex, two monohydrogen and two dihydrogen mirex derivatives, and chlordecone on several hepatic parameters were studied 2 days following a single oral dose of 100 mg/kg in female rats. All compounds increased microsomal cytochrome P-450 content, NADPH-cytochrome c reductase activity, and hepatic ascorbic acid concentration. Microsomal protein concentration was generally increased. All compounds except chlordecone increased relative liver weight and the activities of aminopyrine N-demethylase and p-nitroanisole O-demethylase. Hepatic concentration of protein and glutathione were unaltered. The dechlorinated mirex derivatives caused effects of a magnitude similar to that of mirex, whereas chlordecone was considerably less potent.
Subject(s)
Chlordecone/pharmacology , Insecticides/pharmacology , Microsomes, Liver/drug effects , Mirex/pharmacology , Mixed Function Oxygenases/metabolism , Oxidoreductases/metabolism , Animals , Cytochrome P-450 Enzyme System/metabolism , Female , Hepatomegaly/chemically induced , Microsomes, Liver/enzymology , Mirex/analogs & derivatives , Rats , Rats, Inbred StrainsABSTRACT
Treponema require long-chain fatty acids for growth in vitro. Serum, added to culture media, provides a source of long-chain fatty acids. These fatty acids, however, are esterified to triglycerides, phospholipids, and cholesterol. In this study, the major pathways of complex lipid catabolism in T. phagedenis, T. denticola, T. refringens, T. minutum, and T. vincentii were investigated. Lipase activity was demonstrated in five Treponema species using four lipid substrates. Chromatographic data demonstrated that, during growth, treponemes completely utilized lysophosphatidylcholine, present in serum-supplemented culture media, while phosphatidylcholine and phosphatidylinositol were not utilized. Phospholipase B and glycerophosphorylcholine diesterase activities were demonstrated in the five species of Treponema studied. Treponema phagedenis and T. denticola had phosphatase activity, while T. refringens, T. minutum, and T. vincentii did not have an acid phosphatase activity. Phospholipase A, C, and D and alkaline phosphatase activities were not found in five species of Treponema. Based on the enzymes demonstrated in this study, two pathways of phospholipid catabolism are proposed.
