Studies on hepatic mitochondrial cytochrome P-450 during Plasmodium yoelii infection and pyrimethamine treatment in mice.

Hepatic mitochondrial cytochrome P-450 and b(5) activities were significantly depressed, whereas heme and hemozoin were increased during Plasmodium yoelii infection. Type II, aniline-HCl binding efficacy and polyacrylamide gel electrophoretic profile also depicted impairment of cytochrome P-450 during infection. However, the above alterations were more pronounced in the infected hepatic mitochondria, compared to microsomes. Oral treatment of pyrimethamine (10 mg/kg body weightx4 days) to P. yoelii-infected mice brought the altered levels of mitochondrial and microsomal cytochrome P-450 and b(5) to almost normal, whereas heme and hemozoin levels remained unchanged.