Jpn. J. Pharmacol. 84 (2), 101-112 (2000)

Therapeutic Strategies in Alzheimer's Disease: M1 Muscarinic Agonists

Abraham Fisher*

Israel╩Institute for Biological Research, P.O.Box 19, 74100 Ness-Ziona, Israel
*Corresponding author.╩╩FAX:+972-8-9381-615

Abstract: The cholinergic hypofunction in Alzheimer's disease (AD) appears to be linked with two other major hallmarks of this disease, b-amyloid and hyperphosphorylated tau protein. Formation of b-amyloids might impair the coupling of M1 muscarinic acetylcholine receptors (mAChR) with G-proteins. This can lead to decreased signal transduction, a decrease of trophic and non-amyloidogenic amyloid precursor protein (APPs) and generation of more b-amyloids, aggravating further the cholinergic deficiency. This review is an attempt to explore the M1 mAChR regulation of b-amyloid metabolism, tau hyperphosphorylation and cognitive functions. The therapeutic potential of M1-selective muscarinic agonists including AF102B, AF150(S), AF267B (the AF series) is evaluated and compared, when possible, with several FDA-approved acetylcholinesterase inhibitors. These M1 agonists can elevate APPs, decrease tau protein phosphorylation/hyperphosphorylation in vitro and in vivo and restore cognitive impairments in several animal models for AD. Except for the M1 agonists, no other compounds were reported yet with combined effects; e.g., amelioration of cognition dysfunction and beneficial modulation of APPs/b-amyloid together with tau hyperphosphorylation/phosphorylation. This property of M1 agonists to alter different aspects associated with AD pathogenesis could represent the most remarkable clinical value of such drugs.

Keywords: Alzheimer's disease, M1 muscarinic agonist, Animal model, b-Amyloid, Tau

Copyrightę The Japanese Pharmacological Society 2000

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