GW 501516 (Endurobol) is a effective and highly specifc PPARβ/δ agonist (EC50: 1 nM), with 1000-fold selectivity over hPPARα/γ.

GW 501516 is the most potent and selective PPARδ agonist, with an EC50 of 1.1 nM against PPARα and 1000-fold selectivity over other human subtypes, PPARα and -γ[1]. It exhibits anti-inflammatory effects in mouse cultured proximal tubular (mProx) cells, inhibiting palmitate- and TNFα-induced increases in MCP-1 mRNA expression in a dose-dependent manner[3].

GW 501516 adversely affects bone formation, resulting in reduced bone mineral density (BMD) and compromised bone integrity in ovariectomized (OVX) rats[2]. Additionally, it mitigates interstitial inflammation and damage to proximal tubular cells in a mouse model of protein-overload nephropathy[3]. Furthermore, treatment with GW 501516 improves running endurance and increases the number of succinate dehydrogenase (SDH)-positive muscle fibers in both conditioned and unconditioned mice[4].

Tyrosine Kinase Assays: Enzyme assays for determination of IC50 are performed in 96-well filter plates in a total volume of 0.1 mL, containing 20 mM Hepes, pH 7.4, 50 mM sodium vanadate, 40 mM magnesium chloride, 10 μM adenosine triphosphate (ATP) containing 0.5 mCi of [32P]ATP, 20 mg of polyglutamic acid/tyrosine, 10 ng of EGFR tyrosine kinase, and appropriate dilutions of CI-1033. All components except the ATP are added to the well and the plate is incubated with shaking for 10 min at 25 °C. The reaction is started by adding [32P]ATP, and the plate is incubated at 25 °C for another 10 min. The reaction is terminated by addition of 0.1 mL of 20% trichloroacetic acid (TCA). The plate is kept at 4 °C for at least 15 min to allow the substrate to precipitate. The wells are then washed five times with 0.2 mL of 10% TCA and 32P incorporation determined with a Wallac β plate counter.

GW 501516 is dissolved in DMSO. Cells are starved by incubation in 0.2% FCS DMEM for 9 h, then pre-incubated with GW 501516, at a final concentration of 2.5 and 5 μM, or 0.05% DMSO as control for 3 hours, followed by stimulation with 150 μM palmitate bound to 8.0% BSA for 12 h[3].