Professor Arthur Robertson Cushny

6 March 1866 - 25 February 1926

Arthur Cushny was born in Fochabers, a son, grandson and great-grandson of the Manse. Graduating MA from University of Aberdeen in 1886 and thereafter MB CM in 1889, he quickly developed an interest in pharmacology and physiology and, having won a George Thompson fellowship from the University, set off to study initially in Berne under Konecker, and thereafter Strasbourg under Schmiedberg, the then doyen of European pharmacology.

He quickly developed a reputation as a scientist in that department, and in 1893 was “head-hunted” to take up the key position, at the age of 27, of Professor of Pharmacology at the University of Michigan, Ann Arbour. He developed a formidable reputation as teacher and researcher, becoming one of the noted clinical academics of his generation. He introduced a completely revolutionary approach to the subject of Materia Medica. This has previously been largely based on empiricism, mysterious botanicals and opinion. Cushny embraced the new science of pharmacology emerging from the great laboratories of Germany, and of evidence-based treatments based on pharmacological principles (as well as they were understood at that time). This culminated in one of his main accomplishments there was to write a textbook of Pharmacology – the first in the English-speaking world – "Pharmacology and Therapeutics, or the action of drugs". This was so well and widely received that it became the gold-standard textbook on the subject for the next thirty years.

After a highly productive 12 years in Michigan, he accepted the invitation to take up a chair of Pharmacology at University College, London. Here the “Department” was little more than a single room, but with the aid of a gift from his fellow Scotsman made good in America – Andrew Carnegie – he set about building a Department of formidable potential, having taking steps in the process to collaborate with Dr (later Sir) James Mackenzie, then the leading clinical authority on cardiac rhythm disturbances.

In his final move, he was persuaded in 1918 to accept the post of the Chair of Pharmacology at the University of Edinburgh. For years prior to that research in that Department had been allowed to lapse but he again brought his formidable intellect and organisational ability to bear and completely reinvigorated that Department such that it became one of the most active in the country. His sudden collapse and death at home from a probable cerebral haemorrhage on 25 February 1926, just weeks before his 60th birthday, was recognised by colleagues globally as an irreparable loss to medical science.

Cushny’s scientific reputation centred on four main areas.

In his time at Michigan and UCL, he became a world authority on the mode of action of digitalis, producing many ground breaking studies on the mammalian heart. Cushny demonstrated that digitalis had two major properties – it was able to slow the heart rate probably by directly stimulating the vagus nerve, but also by a direct effect on the myocardium itself, and it could also stimulate ventricular contraction. He was able to discount a direct effect on the kidney and concluded that the beneficial effect in heart failure was via its cardiac action rather than a renal effect. He also showed that at toxic doses digoxin could have adverse stimulatory effects on the myocardium, provoking fibrillation.

During his studies with digitalis in dogs, he made what is now regarded as his most noteworthy observation. He had observed that in dogs a specific type of arrhythmia occurred in the auricles, thereby provoking a secondary rapid and chaotic ventricular response – auricular fibrillation. He had been aware of a condition in certain patients with heart disease known as delirium cordis, where the heart rate was rapid and irregular, and that this generally carried a poor prognosis. Until then that was considered to be a condition arising from and affecting the ventricles. Cushny, in his detailed paper of 1892 acknowledges (having no doubt been aware of the work of John MacWilliam in Aberdeen) that delirium cordis when caused by fibrillary contractions of the ventricle usually causes cardiac arrest, but notes that a similar chaotic movement of the auricles in dogs may continue for a long time without proving fatal, and speculated that the same might occur in man.: “I do not wish to assert that the clinical delirium cordis with the physiological delirium auriculae, but the resemblance is certainly striking.” Much of the main body of the paper is given to development of the thesis that irregularity of both the mammalian and human heart may be due to disorders arising not just in the ventricles – as had been previously thought, but also in the auricles. His concluding statement is reserved, as one might expect from a responsible scientist, but he is clearly proposing the hypothesis that auricular fibrillation might occur in man. In 1906 he published with his colleague Charles Edmunds, a case report of a patient they had been observing since 1901 concluding that the dramatic variation in pulse rate was most likely due to “ irregular discharge  of irregularities from the atrium and not to defects in the contraction of the ventricle, which appears to respond to the impulses received.” This is probably the first clinical description of atrial fibrillation, later to be confirmed on electrocardiography by Sir Thomas Lewis in 1910. Cushny presented his clinical findings in Aberdeen at a meeting to mark the Quarter centenary celebrations of the University in 1906. He summarised his own and previous work in this complex field in a monograph. "The Action and Uses in Medicine of Digitalis and its Allies" (Nature volume 116pages89; 1925).

His studies on digoxin led Cushny into another line of work, investigating the secretory function of the kidney. Prior to this the hypothesis had been that water and inorganic salts were secreted by the glomerular cells and thereafter urea and uric acid were secreted by the tubular cells of the kidney – the so-called simple diffusion model of Heidenham. Cushny found data to refute this and proposed the “modern model”, formerly proposed by Ludwig, to be more consistent with his experimental data, namely that of glomerular filtration followed by differential tubular reabsorption, with individual sulutes governed by their own individual reabsorption charecteristics. He published his work in a major monograph "The Secretion of the Urine" (Nature volume 99, page304; 1917), and the modern theory remains in very large part, the accepted version of renal excretory function to this day.

His other area of interest and expertise lay in assessing drug action in vivo. He was first to suggest the use of animals for assessing the relative activity of different preparations of  drugs such as digitalis, many of which were still at that time derived from herbal extracts. This was introduced in commercial practice in the late 1890’s. It would be inconceivable now that drugs might be used in man without extensive prior testing in animals, and Cushny might well be said to have been the originator of this practice. A further major interest was to flow from this work. Following the lead of Pasteur 50 years earlier, while working on the effects of drugs on the mammalian heart, Cushny initially demonstrated that whereas atropine was a powerful stimulant of the central nervous system, its L- isomer hyoscyamine, whilst equally active on the mammalian heart, had double the stimulant effect on the nervous system.  Several papers on this complex topic followed and these were summarised, with a review of the literature, in his final monograph, published posthumously, "Biological Relations of Optically Isomeric Substances" (Nature volume 120page152; 1927).

At the time of his untimely death, Arthur Cushny was recognised by his peers and colleagues as a pharmacologist/physiologist of international stature. With his encyclopaedic knowledge, formidably laboratory skills, penetrating observational power and a track record of organisational ability, he was one of the foremost clinical scientists of his generation. 

 

Chair, Pharmacology, University of Michigan, 1893 – 1905
Chair, Pharmacology, University College, London, 1905 – 1918
Chair, Materia Medica & Pharmacology, University of Edinburgh, 1918 – 1926

FRS (1907)
LLD  (1911 University of Aberdeen)
FRSE (1919)
LLD (1925 University of Michigan)

image: Wellcome Collection. Attribution 4.0 International (CC BY 4.0)

Biography prepared from the nomination made by Prof J Webster to the University of Aberdeen 525 Alumni project.