PURINOCEPTOR-MEDIATED MODULATION OF PURINE AND NEUROTRANSMITTER RELEASE FROM NERVOUS-TISSUE

The purpose of this review is to analyse critically our present knowle dge on purine release, and in particular the role of these substances as modulators of the nervous transmission. Multiple purine receptor su btypes have been identified, cloned and functionally characterised. Ne urons and glial cells are considered to be important sources of extrac ellular adenine-based purines. The released nucleotides and nucleoside s, by interacting with their specific neuronal and glial receptors, ac tivate a complex autocrine and/or paracrine system for the modulation of the release either of neurotransmitters or the purine ones. Guanine -based purines which are released from astrocytes co-operate with aden ine-based compounds in this modulation. (C) 1998 The Italian Pharmacol ogical Society.