Table 1

V_max and K_m values for P450-mediated selegiline metabolism to desmethylselegiline and levomethamphetamine

	Desmethylselegiline
	CYP Content	K_m	V_max	V_max/K_m	Hepatic Clearance	Hepatic Clearance
	pmol/mg	μM	pmol/pmol/min	ml/μmolP450^min*	l/h	% of total
1A1	^1-b	161	7	43	0	^1-b
1A2	50	334	12	36	7	6
2A6	66	376	5	13	3	3
2B6	26	25	52	2055	62	57
2C8^1-a	^1-b	82	3	37	^1-b	^1-b
2C9	55	628	3	5	1	1
2C19	26	20	7	350	26	24
2D6	11	^1-c	^1-c	^1-c	^1-c	^1-c
2E1	53	678	7	10	2	2
3A4^1-a	127	608	10	16	8	7

	Levomethamphetamine
	CYP Content	K_m	V_max	V_max/K_m	Hepatic Clearance	Hepatic Clearance
	pmol/mg	μM	pmol/pmol/min	ml/μmolP450^min*	l/h	% of total
1A1	^1-b	117	10	85	0	^1-b
1A2	50	379	32	84	14	9
2A6	66	^1-c	^1-c	^1-c	^1-c	^1-c
2B6	26	33	65	1994	62	40
2C8^1-a	^1-b	630	7	11	0	^1-b
2C9	55	252	2	8	2	0
2C19	26	20	30	1500	56	36
2D6	11	^1-c	^1-c	^1-c	^1-c	^1-c
2E1	53	437	6	14	3	2
3A4^1-a	127	612	28	46	19	12

The subsequent calculation of hepatic clearance uses the conversion factors described under Materials and Methods. The contribution of each specific enzyme to the hepatic clearance is also shown. The data for the specific P450 content were from GENTEST (http://www.gentest.com/prod_inserts/H161_2.htm#immunoquantitation).

↵1-a Including human cytochrome P450 reductase and cytochrome b₅.
↵1-b P450 content not provided.
↵1-c Below the limit of detection.