Current Pharmaceutical Design - Volume 8, Issue 26, 2002

The synthesis and the pharmacological activity of alkynyl derivatives of adenosine (Ado) and Nethylcarboxamidoadenosine (NECA), that have been tested on adenosine receptors from different sources, have been reviewed. Most of compounds have been characterized in the last ten years by using radioligand binding assays on rat brain membranes and functional studies on different animal models. More recently, the four hu Read More

Adenosine, a widely distributed modulator, regulates many physiological functions through specific cell membrane G-protein-coupled receptors classified as A1, A2A, A2B and A3. An intense medicinal chemistry effort made over the last 20 years has led to a variety of selective adenosine receptor agonists and antagonists. In particular, the pyrazolo-triazolo-pyrimidine nucleus has been strongly investigated in the last years Read More

Novel phenomena, such as constitutive activity and inverse agonism, have led to a ligand (re)classification along an agonists-neutral antagonist-inverse agonist continuum. This review focuses on adenosine A1 receptor ligands and their intrinsic activity (α). The intrinsic activity of a ligand depends both on the chemical characteristics of the compound itself and on the experimental conditions in which it is assayed. Consequ Read More

In the last decade the field of purinergic pharmacology has continued to grow as the complexity of the receptor families and the various enzymes involved in purine metabolism have been defined in molecular terms. Adenosine receptors (ARs) are currently divided into the four subclasses A1-, A2A-, A2B- and A3AR. The most intensively studied subtypes are the high-affinity A1 and A2A receptors, which are activated by adenosin Read More

Pyrimidine nucleotides, including UTP, UDP and UDP-glucose, are important signaling molecules which activate G protein-coupled membrane receptors of the P2Y family. Four distinct pyrimidine nucleotide-sensitive P2Y receptor subtypes have been cloned, P2Y2, P2Y4, P2Y6 and P2Y14. Pharmacological experiments indicate that further subtypes may exist. P2Y2 and P2Y4 receptors are activated by UTP (the P2Y2 and th Read More

Extracellular adenine and uracil 5'-nucleotides are important signalling molecules that exert a great variety of effects in numerous tissues and cell types through the activation of P2 receptors. In the past eight years, an extended series of P2 receptors (P2X1-7, ionotropic subunits, P2Y1,2,4,6,11,12, metabotropic receptors) has been cloned from vertebrate tissues. In this rapidly expanding field, one of the main curr Read More

Nucleotides are emerging as an ubiquitous family of extracellular signaling molecules. These effects are mediated through a specific class of plasma membrane receptors called P2 receptors that, according to the molecular structure, are further subdivided into two subfamilies: P2Y and P2X. Specifically, P2X-receptors are ligand-gated ion channels, whereas P2Y-receptors belong to the superfamily of G-protein-coupled re Read More