Immunosuppressant deoxyspergualin affects mitochondrial respiratory function in growing cells.

experiments. DSGhas been found to interact intracelluarly with Hsc70, a constitutively expressed memberof the heat shock protein 70 (Hsp 70) family4), but the mechanism of action of DSGstill requires further explanation. We have used methyldeoxyspergualin (MeDSG) for in vitro culture studies of DSG, because it is more stable to hydrolysis than DSG but still possesses a similar immunosuppressive activity. Recently, we found that rapidly dividing cells are more sensitive to MeDSGthan slowly growing cells and that MeDSG inhibits cell growth, followed by apoptosis. Quiescent cells are resistant to MeDSG5). Tetrazolium salts such as MTT (3-(4,5-