Development of protoporphyria in C57BL/10ScSn mice after CP94. (A) Accumulation of hepatic porphyrins expressed as protoporphyrin. Mice were administered CP94 in the drinking water (2 mg/mL) for up to 15 weeks. Results are mean ± SD from 3 to 8 mice per group. (B) HPLC of liver porphyrins after 2 weeks of exposure to CP94. (a) control, (b) CP94, and (c) standard protoporphyrin.