US EPA

2200154 

Journal Article 

Abstract 

Effects of mirex and chloroquine on PCB-induced hepatic porphyria in the rat 

Fulfs, JC; Abraham, R 

1976 

1 

Toxicology and Applied Pharmacology
ISSN: 0041-008X
EISSN: 1096-0333 

37 

1 

119-120 

English 

WOS:A1976BZ49700076 

has other version or edition 2204627 Hepatocellular responses and species variation to organochlorine compounds
is part of a larger document 3221920 Abstracts of papers for the Fifteenth Annual Meeting of the Society of Toxicology, Atlanta, Georgia

As a continuation of previous work, PCB (Aroclor 1221) and mirex were given to rats by oral gavage for up to 17 months: Group I, PCB (25 mg/kg); Group II, mirex (1.5 mg/kg); Group III, PCB (25 mg/kg) and mirex (1.5 mg/kg); and Group IV, corn oil. Hepatic centrilobular hypertrophy was initially observed at 3 months in all experimental groups but was most marked in Group III. This condition was enhanced at 6 and 17 months and in Group III hypertrophy of hepatocytes extended into the midzonal regions with occasional focal necrosis. Hepatocytes in the centrilobular area contained granules in Groups I and III, which were first noted at 6 months; their number increased with time. Lysosomal acid phosphatase activity was present at similar sites as the granules. These granules were identified as porphyrins as determined histochemically and biochemically. Ultrastructurally, the porphyrins appeared as dense granular inclusions within single membrane-bound vacuoles which contained acid phosphatase activity (lysosomes) and were localized near bile canaliculi. Group II livers had no such granules. At 17 months, an increase in porphyrin granules was observed in Group I and III. In Group III, however, these granules extended throughout the liver lobule. While mirex appeared to have enhanced for formation and retention of porphyrins in lysosomes in Group III, chloroquine had the exact opposite effect. Twenty-four hours following chloroquine treatment, there was a complete absence of ''porphyrin-laden lysosomes,'' suggesting a rapid labilization and exocytosis of these structures. Proliferation of smooth endoplasmic reticulum was noted in all experimental groups that was accompanied by a loss of glucose-6-phosphatase activity. (Author abstract by permission, abstract no. 67)