Comparison of the effects of selective III, IV and nonselective phosphodiesterase inhibitors on isolated tracheal preparations in streptozotocin-diabetic rats

The aim of the present study was to investigate the relaxant effects of sel ective III, IV and nonselective phosphodiesterase inhibitors, e.g. amrinone , rolipram and theophylline, respectively, on isolated tracheal preparation s in streptozotocin (STZ)-diabetic rats. Six weeks before the experiments, the rats to be made diabetic were anesthetized with diethyl ether and diabe tes was then induced by a single intravenous injection of STZ (65 mg kg(-1) ) via the tail vein. All drugs produced concentration-dependent relaxations of tracheal preparations precontracted with 10(-6) mol/l carbachol. The re sponses of phosphodiesterase inhibitors were marked in the diabetic groups compared to the control group, but it was found that only amrinone response s are significantly higher in the diabetic groups. Copyright (C) 2000 S. Ka rger AG, Basel.