EXPRESSION OF RAT CGMP-BINDING CGMP-SPECIFIC PHOSPHODIESTERASE MESSENGER-RNA IN PURKINJE-CELL LAYERS DURING POSTNATAL NEURONAL DEVELOPMENT

The cDNA encoding rat cGMP-binding, cGMP-specific phosphodiesterase (c GB-PDE) was isolated from a rat lung cDNA library. Although the deduce d amino acid sequence showed 93.4% similarity with that of bovine cGB- PDE, the N-terminal portion of rat cGB-PDE was extremely different fro m that of bovine. Northern blot analysis indicated that cGB-PDE transc ripts in rats were expressed not only in aorta and lung, but also in s everal other tissues including cerebellum. fn situ hybridization analy sis demonstrated that cerebellar expression of cGB-PDE was confined to Purkinje cell layers in adult rats. To clarify the role of cGB-PDE in the cerebellum, we investigated expression of cGB-PDE mRNA in rats of various apes. cGB-PDE mRNA was not observed in the cerebellum of newb orn rats, but levels of a cGB-PDE mRNA were markedly increased between 4 days and 28 days of age and reached a maximum ill eight-week-old ra ts. In this study, we suggest that cGB-PDE plays important roles not o nly in regulating the relaxation of vascular vessels, but also in esta blishing neuronal networks in the cerebellum at an early postnatal sta ge. In addition the NO/cGMP/cGB-PDE pathway appears to be essential fo r the induction of long-term depression.