Types of pharmacological action at autonomic ganglia / by W.D.M. Paton.

  • William Paton
Date:
1954
Catalogue details

Licence: In copyright

Credit: Types of pharmacological action at autonomic ganglia / by W.D.M. Paton. Source: Wellcome Collection.

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    al., 1949; Bogdanski and Karczmar, 1953, Hutcheon, 1953). Panto¬ caine (Krause, 1951) has been shown to lessen the sensitivity of ganglia to acetylcholine. Pethidine and quinidine, both (amongst other actions) local anaesthetics (Dutta, 1949), can produce ganglionic block, and pethidine will block the ganglion to injections of acetylcholine (Hebb & Konzett, 1949). With this view of the action of these amines in mind, one can turn to consider three other rather special amines, atropine, eserine and adrenaline. The suggestion that atropine could paralyse ganglia originated in experiments such as those by Ambache (1949) in which, on the perfused superior cervical ganglion, he showed that atropine could interfere with the stimulant action of synthetic muscarine-like Compound 2268 F and, in larger doses, could abolish the stimulant effect of acetylcholine. More detailed analysis has confirmed that in fact block of the ganglion can be achieved with atropine, with retention of the response to postganglionic excitation (Cahen and Tueda, 1952; Gyermek & Sztanyik, 1953; Dutta 1949; Fink and Cervoni, 1953). But it is also known now that atropine is quite an effective local anaesthetic, about half as active as procaine (de Elio, 1947). So that despite the relationship of the drug to acetylcholine peripherally, it may well be that its blocking action depends more on its local anaesthetic action than on a strict competition. With eserine, likewise, it is interesting to note that 1) it can produce an insensitivity of the ganglion to acetylcholine (Feldberg and Vartiainen, 1934; Paton and Perry, 1952) without depolarization; 2) it can (under special conditions recently described by Perry, 1953) depress acetylcholine release; 3) it can interfere with transmission in peripheral nerve (Bullock, Nachmansohn and Rothenberg, 1946; Paton and Thompson, unpublished). Despite its dominant anti¬ cholinesterase effect, the possibility seems a real one that eserine also has another action, unrelated to its main one, which links it to local anaesthetic amines rather than to quaternary competitive drugs. The blocking action of adrenaline at the ganglion, described by Burn and Bulbring (1942), for relatively large doses of adrenaline, (facilitation of transmission being obtained with small doses; cf. Konzett, 1950), and by Marrazzi (1939), provides a third case of a ganglionically active amine that may be of the same kind. Paton and Thompson (1953 b) have obtained evidence that adrenaline will depress the release of acetylcholine in the perfused ganglion, and further that adrenaline in a concentration of 300-1000 fig/cc can some¬ times depress conduction in the frog’s sciatic nerve (after removal of