| First Author | Gorman N | Year | 1999 |
| Journal | Biochem Pharmacol | Volume | 58 |
| Issue | 2 | Pages | 375-82 |
| PubMed ID | 10423181 | Mgi Jnum | J:55743 |
| Mgi Id | MGI:1339277 | Doi | 10.1016/s0006-2952(99)00088-x |
| Citation | Gorman N, et al. (1999) Role of small differences in CYP1A2 in the development of uroporphyria produced by iron and 5-aminolevulinate in C57BL/6 and SWR strains of mice. Biochem Pharmacol 58(2):375-82 |
| abstractText | Previous work has implicated CYP1A2 in experimental uroporphyria caused by poly-halogenated aromatic compounds, and in uroporphyria caused by iron and 5-aminolevulinate (ALA) in the absence of inducers of CYP1A2. Here we examined whether the different susceptibilities of SWR and C57BL/6 strains of mice to uroporphyria in the absence of inducers of CYP1A2 are related to different levels of CYP1A2. Enzymological assays (ethoxy- and methoxyresorufin dealkylases, and uroporphyrinogen oxidation) and immunoblots indicated that there was about twice the amount of hepatic CYP1A2 in SWR mice compared with C57BL/6 mice. Immunohistochemistry revealed that CYP1A2 was located centrilobularly in the liver, and the staining was more intense in SWR mice than in C57BL/6 mice. Hepatic non-heme iron was about double in SWR compared with C57BL/6 mice. In SWR mice given iron dextran, hepatic iron was 1.7-fold that of C57BL/6 mice given iron dextran. SWR mice administered ALA in the drinking water accumulated much less hepatic protoporphyrin than did C57BL/6 mice. To confirm the importance of small increases in CYP1A2, C57BL/6 mice were given a low dose of 3-methylcholanthrene (MC) (15 mg/kg), as well as iron and ALA. There was about a 5- to 6-fold increase in hepatic uroporphyrin accumulation after 32 days on ALA compared with animals not given MC. In these animals, CYP1A2 was increased by 10-fold at 2 days, but returned to basal levels by 14 days. We conclude that small and transient differences in CYP1A2 may be important in the development of uroporphyria. |
