In vitro bioactivation of ximelagatran via ethyl-melagatran (H338/57) and N-hydroxy-melagatran (H415/04) to melagatran (H319/68) by liver and kidney microsomes and mitochondria of pig and human
| Enzyme Source | Products | ||
|---|---|---|---|
| Ethyl-melagatran | N-Hydroxy-melagatran | Melagatran | |
| nmol/min/mg protein | μM | ||
| Pig liver microsomes | 0.77 ± 0.07 1-a | 14.19 ± 0.63 | 43.76 ± 1.80 1-b |
| Human liver microsomes | N.D. | 37.38 ± 1.60 | 37.80 ± 1.08 |
| Pig liver mitochondria | 5.98 ± 0.16 | 3.39 ± 0.09 | 65.64 ± 2.16 |
| Human liver mitochondria | 0.16 ± 0.01 | 17.14 ± 0.54 | 32.76 ± 0.72 |
| Pig kidney microsomes | 2.50 ± 0.16 | 14.31 ± 0.09 | 68.60 ± 1.57 |
| Human kidney microsomes | 0.88 ± 0.03 | 0.31 ± 0.02 | N.D. |
| Pig kidney microsomes | 8.38 ± 0.17 | 2.47 ± 0.06 | 9.06 ± 0.45 |
| Human kidney mitochondria | 1.69 ± 0.11 | <0.21 | 0.56 ± 0.32 |
The incubation mixtures have been optimized for protein content, NADH concentration, and substrate concentration. An incubation mixture consisted of 0.3 mg/ml microsomal or mitochondrial protein of liver or 0.15 mg/ml of kidney (human or pig), 0.5 mM ximelagatran as substrate, and 1 mM NADH as cosubstrate in 100 mM potassium phosphate buffer pH 7.0. For incubation conditions and HPLC analysis, see Materials and Methods.