Table 4.

V_max, K_m, CL_int, K_i and [I]/K_i for the disappearance of DA-8159 and for the formation of DA-8164 with and without metformin, or the disappearance of metformin with and without DA-8159 in intestinal microsomal fractions

Parameter	DA-8159	Parameter	Metformin
	Without metformin	With metformin		Without DA-8159	With DA-8159
Disappearance of DA-8159			Disappearance of metformin
Vmax (nmol min–1 mg protein–1)	81.6±24.9	96.1±21.9	Vmax (nmol min–1 mg protein–1)	107±43.5	134±36.9
Km (μM)	0.166±0.0252	0.226±0.0940	Km (μM)	0.284±0.101	0.347±0.159
CLint (μl min–1 mg protein–1)	2.14±0.565	2.30±0.527	CLint (μl min–1 mg protein–1)	2.84±1.11	2.59±1.01
Ki (μM) for the inhibition of metabolism of metformin	11.2–32.6		Ki (μM) for the inhibition of metabolism of DA-8159 (formation of DA-8164)	50.2–86.2 (11.0–35.9)
[I]/Ki for the inhibition of metabolism of metformin	0.199–0.346		[I]/Ki for the inhibition of metabolism of DA-8159 (formation of DA-8164)	0.0700–0.120 (0.168–0.548)
Formation of DA-8164
Vmax (nmol min–1 mg protein–1)	52.0±26.1	46.6±11.1
Km (μM)	0.0550±0.0160	0.0693±0.0187
CLint (μl min–1 mg protein–1)	1.19±0.364	1.54±0.562

Data are expressed as mean±s.d. (DA-8159 without metformin, DA-8159 with metformin, n=4; metformin without and with DA-8159, n=5).