A 922500

A 922500 (DGAT-1 Inhibitor 4a) is a potent, selective, and orally bioavailable diacylglycerol acyltransferase 1 (DGAT-1) inhibitor with IC₅₀s of 9 and 22 nM against human and mouse DGAT-1, respectively. IC50 & Target:IC50: 9 nM (human DGAT-1), 22 nM (mouse DGAT-1)^[1] In Vitro: A 922500 (A-922500) demonstrates excellent selectivity over other acyltransferases, including DGAT-2 (IC₅₀=53 μM) and the phylogenetic family members acyl coenzyme A cholesterol acyltransferase-1 and -2 (IC₅₀=296 μM) ^[1]. In Vivo: DGAT-1 inhibitor A 922500 (A-922500) reduces serum triglyceride levels from baseline at all doses tested; however, this is only statistically significant at the 3 mg/kg dose, which lowers serum triglycerides by 53%. Similarly, the 3 mg/kg dose of A 922500 significantly reduces serum FFA concentrations by 55% and total cholesterol by 25%. DGAT-1 inhibition has no significant effect on body weight at any dose tested. Although A 922500 dpes not significantly affect LDL-cholesterol or HDL-cholesterol individually, the serum LDL/HDL-cholesterol ratio is significantly improved by A 922500 at 0.3 and 3 mg/kg. Similar to the dyslipidemic hamster, treatment with 3 mg/kg A 922500 significantly reduces serum triglyceride concentrations (39%). FFA levels significantly increase over the 14-day period in vehicle-treated animals. This increase is inhibited in a dose-dependent manner by A 922500 such that FFA concentrations are 32% lower after 14 days of treatment with the DGAT-1 inhibitor at 3 mg/kg, compared with the vehicle group (p < 0.05). HDL-cholesterol is significantly increased from baseline levels by A 922500 at 0.3 and 3 mg/kg; however, this is only significantly increased compared with vehicle at the 3 mg/kg dose. Body weight significantly increases over the 2-week period in vehicle-treated rats, and this is not affected by A 922500. LDL-cholesterol is significantly reduced in the vehicle treated group. DGAT-1 inhibition does not further reduce LDL-cholesterol and has no effect on total cholesterol^[1].