Table 2

N-Demethylation activities for CIT in microsomes from human B lymphoblastoid cells expressing P450 isoforms

CYP  Activities
pmol/mg/min pmol/pmol P450/min
1A2ND2-a
2A6ND
2B6ND
2C9ND
2C199.691.39
2D6ND
2E1ND
3A415.940.71

Substrate (100 μM CIT) was incubated at 37°C for 60 min with microsomes (0.5 mg/ml) from human B lymphoblastoid cells expressing CYP2C19 and CYP3A4 or for 120 min with microsomes expressing the other CYP isoforms.

  • 2-a ND, not detectable.