Type IV phosphodiesterase inhibitor suppresses insulin-dependent myocardial glucose uptake

1. Phosphodiesterase (PDE) IV has been localized at cardiomyocytes and the coronary vasculature and modulates cAMP, but the effect of PDE IV on myocardial glucose uptake has not been demonstrated. 2. Glucose uptake in rat isolated hearts treated with the PDE IV inhibitor rolipram was measured by [³¹P] nuclear magnetic resonance spectroscopy. 3. Under non-stimulating conditions, glucose uptake was not significantly different between control and rolipram (1 μmol/L)-treated rat hearts, whereas enhanced uptake in insulin-stimulated conditions was significantly attenuated by rolipram. 4. Phosphodiesterase IV inhibitor negatively affects insulin-dependent myocardial glucose uptake.