Direct-acting cholinergic

Increased stimulation of the AChR can be achieved in two ways (1) by binding of the directly acting cholinergic agonists to the AChR, triggering nicotinic or muscarinic... 

The principal directly acting cholinergic agonists include methacholine, carbachol, and betanechol—agents which, unlike acetylcholine, are used clinically. 

Unlike the systemic direct-acting cholinergic stimulants (e.g., bethanechol), cholinesterase inhibitors display a relative lack of specificity regarding which cholinergic synapses they stimulate. These drugs tend to inhibit the acetylcholinesterase found at... 

An alkaloid of natural plant origin, pilocarpine is a direct-acting cholinergic agonist with a dominant action at both peripheral and central muscarinic sites. The cholinomimetic action of pilocarpine on smooth muscle muscarinic receptors generally results in contraction.The response of intraocular smooth muscle to pilocarpine is pupillary constriction, spasm of accommodation, and reduction of lOP. 

Pilocarpine is direct acting cholinergic used to treat glaucoma, reducing intraocular pressure by constricting pupils and opening the canal of Schlemm, which enable drainage of aqueous humor. 

Continuedfrom previous page) DIRECT-ACTING CHOLINERGIC... 

See direct-acting cholinergic list is provided in the Appendix. Detailed tables show doses, recommendations, expectations, side effects, contraindications, and more available on the book s Web site (see URL in Appendix). 

The work on anticholinesterase dmgs is a good example for the impact of chemical knowledge on the outcome in medicinal chemistry. In this case, a best fit in the enzjnne active site may not be the most active compound, as chemistry of hydrolysis rather than enzyme binding seems to be the determinant factor of activity. Cholinesterase inhibitors have less effect on smooth muscles, thus on blood pressure, than direct acting cholinergic agonists. 

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