Cholinergic blocking agents

The cholinergic blocking agents which mainly include atropine and related alkaloid are obtained from the plant Atropa belladonna (deadly nightshade), Atropa acuminata, Hyoscyamus niger (black henbane) and Datura stramonium (datura) and semisynthetic atropine/hyoscine analogues and synthetic compounds. 

The detailed pharmacology is discussed in chapter Cholinergic blocking agents. ... 

Physochlaina infundibularis Kuang. Hua Shan Seng (root) Hyoscyamine, scopolamine, scopoletin, scoplin.33 This herb is toxic. A cholinergic blocking agent, relaxing effect on bronchial muscles. 

A. Mechanism of Action. BZ (3-quinuclidinyl benzilate) is a cholinergic blocking agent that at single doses of less than 1 mg produces delirium lasting several days. No permanent adverse effects have been reported from clinical studies. BZ is effective by all routes of administration, but its effectiveness percutaneously (when mixed with a suitable solvent) is limited, so that route is not likely to be used. 

In spite of the continuing search for an improved muscarinic cholinergic blocking agent, atropine and its salts are still most widely used in the treatment of intoxication by organophosphate and carbamate inhibitors of cholinesterase. Therefore, the characteristics of this compound in the... 

In this work we have taken advantage of the regional distribution of receptors by using the bovine caudate nucleus as an essentially muscarinic tissue, in comparison with the rat cerebral cortex in which there is a mixture of the two types of receptor sites. With this approach and the use of appropriate cholinergic blocking agents we have reached the conclusion that the PI effect stimulated by ACh in the CNS is mediated only by muscarinic receptors. 

Fig. 1. Action of ACh and of cholinergic blocking agents on the 32pi incorporation into phospholipids of bovine caudate nucleus.

Similar results are shown in Table 3 for the cerebral cortex of the rat. In the control condition the incorporation is much higher in PI than in the other phospholipids. Under the action of ACh there is an activation of 174% in PI turnover, while in the other phospholipids there is no change The results with the cholinergic blocking agents show that while atropine completely blocks the activation by ACh, there is no change with d-tubocurarine. 

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