Ontogeny of rolipram-sensitive, low-K-m, cyclic AMP-specific phosphodiesterase in rat brain

The postnatal development of rolipram-sensitive, low-K-m, cyclic AMP-specif ic phosphodiesterase (PDEA) was investigated in discrete regions of rat bra in using a PDE4 activity assay and immunoblot analyses with K116, a PDE4 an tibody. The V-max for cyclic AMP hydrolysis by PDE4 was lower at birth when compared to adult levels in cerebral cortex, cerebellum, and neostriatum. K-m values for cyclic AMP hydrolysis by PDE4, in contrast, did not change t hroughout the observed period in any brain region tested. The developmental patterns for PDE4 were significantly different among the examined brain re gions. PDE4 activity in olfactory bulb and hippocampus also was found to be lower at birth in comparison to adult levels. Immunoblot analyses showed t hat developmental patterns of PDE4 were significantly different for the var ious subtypes, and also varied substantially across brain regions. The resu lts suggest that PDE4 might be differentially regulated by different ontoge netic events. (C) 1999 Elsevier Science B.V. All rights reserved.