Atropine action

Substances acting antagonistically at the M-cholinoceptor are designated parasympatholytics (prototype the alkaloid atropine actions shown in red in the panels). Therapeutic use of these agents is complicated by their low organ selectivity. Possibilities for a targeted action include ... 

Uses t CO in bradycardia refractory to atropine Action Pi- stimu-... 

Lobeline possesses no atropinic action on the bronchi (93) but broncho-dilator effects may be attributed to the adrenaline discharge which it provokes. 

Obtained as a syrup from plants of the Solanaceae family. Intensely poisonous, its action resembles that of atropine. Sedative in small doses. 

Agent BZ, 3-quinuchdinylbenzilate [6581 -06-2] C22H23NO2, is a typical incapacitant. BZ is one of a group of substances, many of them glycolate esters, sometimes known as atropinemimetics. Their action on the central and peripheral nervous systems resembles that of atropine [51-55-8] ... 

The alkaloid is principally used in medicine to cause dilatation of the pupil of the eye (mydriasis), due to paralysis of the circular muscle of the ns. The accommodation is also paralysed as a result of action on the ciliary muscle (cycloplegia). Atropine is also used in conditions where... 

Hyoscyamine. The natural alkaloid, 1-hyoscyamine and its d-isomeride resemble atropine (dl-hyoscyamine) qualitatively in action, but the 1-form acts more strongly on the peripheral nerves than the d- or dl-forms, though the isomerides appear to have an equal central action. 

Of the proximate derivatives of atropine, the methobromide and the methonitrate are in use for much the same purposes as atropine, but the methonitrate has received special attention for the treatment of pyloric stenosis. opoAtropine has been found by Mancini to retain the same type of action as atropine but to be less potent in peripheral and more active in central nervous action. ... 

Whilst tropyltropine (atropine) is mydriatic, this property is of a low order in benz yltropine and is absent in benzoyl- -tropine. The former is a weak and the latter a potent local anaesthetic. This parallelism in the influence of the tropyl and benzoyl radicals in developing mydriatic and local aniesthetic action respectively, has been shown by von Braun and his co-workers to occur through an extensive series of hydroxyalkylamines in addition to tropine. Considerable modification may be made in the structure of tropine without impairing its capacity for yielding mydriatics anaesthetics. Thus von Braun, Muller and Rath found that e tropyl- and benzoyl-esters respectively of liomotropine (I) and of N-hydroxyalkylnortropanes (III) are comparable with atropine and tropacocaine (derived from tropine (II) and 4-tropine (II) ), respectively... 

Cushny has compared the action of d- and Z-hyoscyamines with that of atropine, and of d-homatropine with that of dZ-homatropine in antagonising the action of pilocarpine, and finds that the order of activity of the first three is in the ratio 1 40 20, and of the second two in the ratio 4 2-5. He drew attention also to the important influence of the acyl radical in the tropeines, which exercises the maximum effect when it is a hydroxyalkyl aromatic residue and is laevorotatory and in illustration of this point gives the following table of relative activities on the basis of capacity to antagnonise pilocarpine in the salivary fistula dog —... 

It resembles atropine in its range of activity but in particular types of action it may differ quantitatively thus its action on the pupil is equal to that of atropine but shorter in duration, and that is also true of its antagonisni to the effect of acetylcholine on the isolated perfused cat s COTt, but its activity on the salivary gland and the blood pressure of the. IS greater than that of atropine, while its action on smooth muscle... 

Trachelantamine, according to Syrneva, has a weak atropine-like action and also produces local anaesthesia. Its hydrolytic product, trache-lantamidine, which is structurally identical with tsoretronecanol, yields a p-aminobenzoyl derivative of -which the crystalline hydrochloride, m.p. 230-2°, is said to be as potent a local anaesthetic as cocaine hydrochloride. The chloro- -heliotridane (p. 606) formed by the aetion of thionyl ehloride on trachelantamidine reacts with 6-methoxy-8-aminoquinoline to form 6-methoxy-8-(pseMdoheliotridylamino)-quinoline,... 

Pilocarpine is being less used in medicine as a diaphoretic in dropsy and similar diseases because of its depressant action on the heart. It has also been employed as a substitute for physostigmine to contract the pupil and reduce intraocular pressure. It has been used as an antidote to atropine, but it does not antagonise the action of atropine in the central nervous system. 

This view was supported by the observation that choline on treatment with nitric acid yielded a product having a pharmacological action similar to that of muscarine as known up to that time. Comparison of the natural and artificial products by Bohm showed that the former was much more active than the latter and that its action was antagonised by atropine, whilst the artificial muscarine had a curare-like action on the atropinised frog. Later, Nothnagel investigated the action of... 

The simplification of the local anesthetic phaimacophore of cocaine to an aryl substituted ester of ethanolamine has been described previously. Atropine (S2) is a structurally closely related natural product whose main biologic action depends on inhibition of the parasympathetic nervous system. Among its many other actions, the compound exerts useful spasmolytic effects. 

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