Rosiglitazone-induced protection against myelotoxicity produced by 5-fluorouracil.

Insulin promotes survival of haemopoietic progenitors. We investigated if rosiglitazone, an insulin sensitizer, could confer protection against 5-fluorouracil (5-FU)-induced myelotoxicity in mice. The decrease in bone marrow cellularity, frequency and content of granulocyte-macrophage progenitors (CFU-GM) characterized myelotoxicity in mice, while insulin sensitivity was determined by hyperinsulinaemic euglycaemic glucose clamping. CFU-GM colony numbers increased in groups pre-treated with rosiglitazone (1.5-6 mg/kg, 5 days), compared to that in mice treated with 5-fluorouracil alone. Since rosiglitazone pre-treatment significantly promoted the clonal expansion of CFU-GM when given in the insulin sensitizing dose, we conclude that rosiglitazone had myeloprotective effects possibly by amplifying endogenous insulin action.