Reversal of the action of adrenaline

George Lindor Brown, 1903-1971

George Lindor Brown—‘Lindor’, ‘Lin’ or ‘G. L.’, never George—was born in Liverpool on 9 February 1903. On his father’s side he came from a family of London tea-merchants. They were well-to-do, but his grandfather, George Alexander Brown, left home as a young man after an argument with his stepfather and joined the army. Eventually he rose to be a colour-sergeant and came with his Irish-born wife Mary Evans to live in Warrington. Their son, George William Arthur Brown, Lindor’s father, was born there. He became a teacher, and soon after Lindor’s birth he returned to Warrington, where he had been appointed headmaster of a large parochial school, the position he held for the rest of his career. G. W. A. was a successful teacher and administrator. He exercised his authority with firmness and good humour, and could easily handle the vicar’s occasional attempts to interfere with the running of his school. He was a well-known figure in Warrington, where among his many activities he took a leading part in starting the men’s club at which he later spent a good deal of his leisure time. His wife, who had been Helen Wharram from Yorkshire, was lively, talkative and competent, and the atmosphere at home was one of cheerful badinage, though G. W. A. had strong opinions on many subjects, and there was no doubt that he was in charge there as well as at school. He and his wife both lived to be elderly and their relationship with their two children continued to be one of mutual affection and respect.

Non-adrenergic non-cholinergic (NANC) transmission to smooth muscle: 35 years on

In 1963, two substances were thought to mediate all transmission between neurons, as well as between nerve and muscle in the peripheral nervous system, namely acetylcholine and noradrenaline. This paradigm primarily was due to the research of Dale, Loewi and von Euler in the first half of the century [Dale, 1937 (Transmission of nervous effects by acetylcholine, Harvey Lect. 32, pp. 229-245)]. However, in 1963, a series of experiments were carried out using recently introduced electrophysiological techniques, which showed unequivocally for the first time that the classical paradigm was not correct. Both inhibitory and excitatory junctions between nerves and smooth muscle cells were shown to exist in which transmission was mediated by non-adrenergic, non-cholinergic (NANC) transmitters. In the succeeding 35 years, identification of these NANC transmitters has been a major task of neuropharmacology, with nitric oxide, neuropeptides, and purines being isolated. This review presents an historical account of the developments this century of the classical paradigm, of how it was displaced, and of the progress made in identifying the neuromuscular transmitters of the autonomic nervous system.

Mechanical responses to catecholamines in isolated strips of the guinea-pig stomach muscle

Effects of catecholamines were investigated on isolated strips of the guinea-pig stomach. In the circular muscles, the relaxation and biphasic response caused by adrenaline and noradrenaline were suppressed partly by phentolamine and also partly by propranolol. The relaxation by catecholamines in the longitudinal muscles was inhibited mainly by propranolol. Thus, there are probably two types of relaxation. Alpha relaxation was more dominant in the circular muscles and beta relaxation in the longitudinal muscles. Contractions in both muscles were mediated through alpha-effects. The circular muscle is more sensitive to the alpha effect and the longitudinal muscle to the beta effect. In the presence of propranolol, isoprenaline. Field stimulation which excited intramural nerves resulted in contraction followed by relaxation in both circular and longitudinal muscles. The inhibition of the electrically evoked contractions by adrenaline and noradrenaline in both circular and longitudinal muscles was abolished by phentolamine but the electrically evoked relaxations were affected little.

Inhibitory and excitatory effects of sympathomimetic amines on muscle strips from the stomach of the guinea-pig

1. Responses of muscle strips from the stomach of the guinea-pig have been recorded. Sympathomimetic amines cause inhibitory, motor or biphasic responses.2. The motor components of the responses of the preparations were greatly enhanced by the removal of the mucosal layers.3. The inhibitory responses to isoprenaline, noradrenaline and phenylephrine were antagonized by propranolol or by sotalol. The inhibitory responses to noradrenaline and phenylephrine but not isoprenaline were antagonized by phentolamine. Therefore, both alpha- and beta-adrenoceptors may subserve inhibition.4. The motor responses to noradrenaline and phenylephrine were often potentiated by propranolol or sotalol and were antagonized by phentolamine. Therefore, motor responses to sympathomimetic amines appear to involve alpha-adrenoceptors.5. The responses to sympathomimetic amines and their antagonists were not modified by hyoscine or by tetrodotoxin. It is concluded that the adrenoceptors mediating the responses recorded from these preparations are located on the smooth muscle cells rather than on a nervous pathway.

Effect of sympathectomy on the response to adrenaline of the blood vessels of the skin in man

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