Muscarinic cholinergic agents

The effects of muscarinic cholinergic agents on memory function have been extensively investigated, and blockade with such agents has been proposed as a possible model for the cognitive failure seen in AD (Sunderland et al. 1988). However, many of the results of such studies can be interpreted as effects on attentional mechanisms or decision processes rather than true memory effects (i.e., effects on encoding, storage, or retrieval) (Beatty et al. 1986). 

Nicotinic Receptor Agonists. There has been significant activity in the development of muscarinic cholinergic receptor agonists for dementia. In addition, agents that interact with nicotinic cholinergic receptors may also have therapeutic value. Nicotinic receptors have been reported to be... 

Agents that increase acetylcholine activity can decrease manic symptoms (e.g, use of cholinesterase inhibitors or augmentation of muscarinic cholinergic activity). 

Costa LG, Kaylor G, Murphy SD. 1990. In vitro and in vivo modulation of cholinergic muscarinic receptors in rat lymphocytes and brain by cholinergic agents. Int J Immunopharmacol 12 67-75. 

Low-potency neuroleptics (e.g., chlorpromazine) Additive effects of blockade of muscarinic cholinergic receptors Anticholinergic effects (dry mouth, tachycardia, possible hyperpyrexia, and delirium) Lower doses of both agents Geller, 1991... 

FIGURE 19-2 Structures of acetylcholine and atropine. Atropine and similar agents antagonize the effects of acetylcholine by blocking muscarinic cholinergic receptors. 

Cyproheptadine, a serotonin and histamine receptor- and muscarinic cholinergic receptorblocking agent, has been used in the treatment of postgastrectomy dumping syndrome and the intestinal hypermotility seen with carcinoid. 

Relief from pain. Selected cholinergic agents have been found that display antinociceptive (analgesic) effects grossly similar to those of morphine. Most of these are nicotinic receptor agonists, but a modest number of muscarinic agonists have been found that also display antinociceptive effects. 

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