The paralysis of autonomic ganglia, with special reference to the therapeutic effects of ganglion-blocking drugs / by W.D.M. Paton.

  • Paton, William D. M.
Date:
[1951?]
Catalogue details

Licence: In copyright

Credit: The paralysis of autonomic ganglia, with special reference to the therapeutic effects of ganglion-blocking drugs / by W.D.M. Paton. Source: Wellcome Collection.

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    3 To Langley’s work with this technique in mapping out the autonomic ganglia we owe much, or even most, of our knowledge of the arrangement of the autonomic ganglia. The most charming if not the most serious- minded tribute to his work in Cambridge may be quoted here: There was a young man of East Anglia Whose nerves were a network of ganglia. As was clear to be seen, He abhorred nicotine, Which makes ganglia Langleyer and Langleyer. Nicotine has proved to be a reliable and fairly specific agent for blocking autonomic ganglia in pharmacological research. But there is one important point about its action which removes it from clinical use. This is the fact that it blocks by depolarization, so that its para¬ lysing action on the ganglia is preceded by a strong stimulation. In attempting, for instance, to paralyse the ganglia controlling the blood pressure, it is necessary to pass through phases in which powerful sympathetic and vagal excitation may in turn be seen, causing a large rise in blood pressure, interrupted by a slowing of the heart, and followed by a further rise due to the release of adrenaline from the suprarenals. In animal experiments one is usually able to wait for these effects to pass before giving a further dose, and can gradually obtain the desired state of complete ganglionic block. But, for clinical practice, the necessity of passing through excitation to obtain paralysis makes nicotine (or any other drug which blocks by depolarizing) unsuitable for use in man. Curare When we turn to curare we come to the first of the other main group of blocking agents—those which block by competition. Curare has been used in analysing ganglionic function since the time of Claude Bernard (1857). Its use in more recent years enabled Eccles (1944) to reveal and analyse the so-called “synaptic potential,” which is the electrical accompaniment of the transmission process at the ganglion synapse, and corresponds to the “ end-plate potential ” at the motor end-plate. Other work has shown that D-tubocurarine (or preparations owing their activity largely to this alka¬ loid) blocks the ganglia of the small intestine (Gross and Cullen, 1945), those controlling the blood pressure (Heymans, 1947), the vagal ganglia in the heart, and