Zotarolimus (ABT-578), an analogue of rapamycin, inhibits FKBP-12 (IC50= 2.8 nM).

In smooth muscle cell （IC50=2.9 nM）and endothelial cell （IC50=2.6 nM）,Zotarolimus effectively inhibits cells proliferation.

Zotarolimus potently inhibits adjuvant DTH(ED50=1.72 mg/kg/day), EAE(ED50=1.17 mg/kg/day), and cardiac allograft rejection(ED50=3.71 mg/kg/day) .

zotarolimus (10 pM-1 μM) in buffer A (2% BSA and 0.2% Tween-20 in D-PBS) is used in the assay of Binding Affinity to FKBP12.

Cell proliferation is assayed by measuring tritiated thymidine incorporation in vitro. Human coronary artery cells (hCa) are seeded into tissue culture flasks for expansion and applied to 96-well plates at desired density in complete media (5000 hCaSMC; 10 000 hCaEC). After 2 days, complete media is replaced with incomplete media to synchronize cells and induce G0 state. Two days later, incomplete media are removed and replaced with complete media (serum/growth factors) to induce G0 to G1 transition. Complete media also contain drug at desired concentrations to determine its effects on cell proliferation. On day 7, 3H-thymidine is added to cells to monitor DNA synthesis, and cells are harvested after overnight incorporation of radioactivity. After an incubation period of 72 h, 25 μL (1 μCi/well) of 3H-thymidine are added to each well. The cells are incubated at 37°C for 16-18 h to allow for incorporation of 3H-thymidine into newly synthesized DNA and the cells harvested onto 96-well plates containing bonded glass fibre filters . The filter plates are air-dried overnight, MicroScint-20 (25 μL) added to each filter well and counted. Drug activity is determined by the inhibition of 3H-thymidine incorporation into newly synthesized DNA relative to cells grown in complete media. (Only for Reference)

Male Sprague-Dawley rats was administrate by intravenous or oral Zotarolimus（2.5 mg/kg）dissolved inethanol: propylene glycol: cremophor EL: D5W vehicle (20: 30: 2: 48, by volume).