Marie-Ange Watson

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We recently demonstrated that the non-classical muscarinic receptor antagonist [3H]pirenzepine ([3H]PZ) identifies a high affinity population of muscarinic sites in the rat cerebral cortex. We now report that cortical muscarinic sites to which [3H]PZ binds with high affinity are modulated by ions but not guanine nucleotides. We also have examined(More)
The specific binding of [3H]pirenzepine ( [3H]PZ) and [3H](-) quinuclidinyl benzilate ( [3H](-)QNB) was investigated in homogenates of human stellate ganglia. [3H]PZ saturation isotherms yielded a Kd of 14 nM and Bmax of 16.7 fmol/mg protein, while [3H](-)QNB binding curves yielded a Kd of 59 pM and Bmax of 33.0 fmol/mg protein. This represents the greatest(More)
Studies with [3H]pirenzepine [( 3H]PZ) suggest that this nonclassical muscarinic antagonist selectively identifies putative M1 muscarinic receptors. We now compare the ontogeny of these putative M1 sites, identified by high-affinity [3H]PZ binding, with sites identified by the classical antagonist (-)-[3H]quinuclidinyl benzilate ((-)-[3H]QNB) in murine(More)
The binding of [3H]pirenzepine to a human neuroblastoma cell line (SH-SY5Y) and its correlation with hydrolysis of phosphatidylinositols were characterized. Specific [3H]pirenzepine binding to intact cells was rapid, reversible, saturable, and of high affinity. Kinetic studies yielded association (k+1) and dissociation (k-1) rate constants of 5.2 +/- 1.4 X(More)
Bilateral microinjections (0.2-2 nmol/site) of a potent M2 muscarinic receptor agonist, cis-methyldioxolane (CD), but not those of a relatively selective M1 receptor agonist (McN-A343; 3 nmol/site), into the intermediate portion of nucleus tractus solitarii (NTS) of pentobarbital-anesthetized rats elicited a decrease in blood pressure (23-52 mm Hg) and(More)
The binding and regulation of selected muscarinic agonists to putative subtypes in rat cerebral cortex and heart were studied. Parallel inhibition studies of [3H]pirenzepine ([3H]PZ) and (-)-[3H]quinuclidinylbenzilate [(-)-[3H]QNB]-labeled membranes were done with and without 30 microM guanyl-5'-yl imidodiphosphate [Gpp(NH)p] at 25 degrees C in 10 mM(More)
The binding of agonists to muscarinic cholinergic receptors is well described by a binding model of multiple affinity states (superhigh, high, and low) in most central and peripheral tissues. Although previous studies of the influences by divalent cations, guanine nucleotides, and sulfhydryl reagents support the concept that these regulators act through(More)
The novel antimuscarinic compound pirenzepine (PZ) has generated considerable interest in the basis and the implications of muscarinic acetylcholine receptor (mAChR) heterogeneity. [3H]PZ has been used extensively to identify and characterize the putative M1 (high affinity for PZ) mAChR subtype, which predominates in central nervous system (CNS) and(More)
The relationship of choline acetyltransferase (ChAT) activity and high affinity binding of the potent and selective sodium-dependent choline uptake inhibitor [3H]hemicholinium-3 ([3H]HC-3) to high-affinity binding of the muscarinic agonist [3H](+)-cis-methyldioxolane ([3H](+)CD), the putative M1 selective antagonist [3H]pirenzepine ([3H]PZ) and the(More)