After 5 hours fast to minimize the contribution of postprandial lipid to the plasma TG concentrations, animals are given lipoprotein lipase inhibitor, poloxamer 407 (1000 mg/kg) or Triton WR-1339 (500 mg/kg) by IP injection. Blood samples are collected prior to and after the injection at time = 1, 2, 4, 8, and 24 hours via tail vein bleeding. Blood levels of TG are measured using an enzymatic assay. Animals are restrained repeatedly for less than a minute each time while blood samples were collected.