Sylvia A. S. Tait

Biochemist who, with her husband, identified aldosterone

Sylvia Agnes Sophia Wardropper, biochemist: born Tumen, Russia 8 January 1917; Research Assistant, Courtauld Institute of Biochemistry, Middlesex Hospital Medical School 1944-55, External Scientific Staff, MRC 1955-58, Research Associate and Co-Director, Biophysical Endocrinology Unit, Department of Physics as Applied to Medicine 1970-82; Senior Scientist, Worcester Foundation for Experimental Geology 1958-70; FRS 1959; married 1940 Flt Lt Anthony Simpson (died 1941), 1956 James F. Tait; died Lymington, Hampshire 28 February 2003.

Sylvia A. S. Tait died only two months before a symposium to be held at the Royal Society on 27-30 April to celebrate the 50th anniversary of the isolation of aldosterone that she achieved with her husband, James F. Tait.

Aldosterone was the last of a series of biologically potent naturally occurring steroid hormones to be isolated and identified during the period from the 1920s to the 1950s, and followed the earlier characterisation of the androgens, oestrogens, and the glucocorticoid hormone, cortisol (hydrocortisone). Like these, the identification of aldosterone, with its "mineralocorticoid" activity, aroused great excitement, and stimulated a new period of research into the regulation of salt and water balance, blood pressure, and cardiovascular disease.

It was first shown to be the hormone secreted by the outermost part of the adrenal gland, the zona glomerulosa of the adrenal cortex, and in recent years the study of this hormone has received a new impetus with the finding that it may also be produced within the vasculature itself. This carries implications for the management of cardiovascular disease, and recent trials of the new aldosterone antagonists show great promise in this regard.

The Taits, as they were fondly and universally known, were one of the great husband-and-wife teams of biological science who, although having been in retirement for 20 years, still maintained a keen interest in the field of aldosterone research and continued to publish, after a total period of 57 years working together.

Sylvia Agnes Sophia Wardropper was born in Tumen, Siberia, in 1917, and returned to England with her family in 1920, not, it can be imagined, without difficulty at that point in history. Her mother was a Russian mathematician, a graduate of Moscow University; rare for a woman in those days, especially in Tsarist Russia. Her father was a Scottish agronomist.

Sylvia Wardropper had a conventional British upbringing and education with an emphasis on languages at a higher school level rather than on science, but in the end she graduated with an honours degree in Zoology from University College London in 1939. In 1940 she married Flt Lt Anthony Simpson, a fellow student from University College, who later flew in RAF Coastal Command and was killed in action near Bergen in 1941. Professionally Sylvia kept the surname Simpson until she married James Tait in 1956.

As a postgraduate Sylvia Simpson first worked on nerve regeneration with the great J.Z. Young in Oxford but, in 1944, she took up a more permanent position at the Courtauld Institute of Biochemistry, as an assistant to P.C. Williams, who was head of the biological laboratories. Simpson was a remarkably skilled biologist who had considerable experience with bioassays for oestrogen at the Courtauld and in the 1950s was conversant with the appropriate statistical methods.

In 1947, the pioneering study of Ralph Dorfman and his colleagues in Cleveland, Ohio, which described a microassay for mineralocorticoid activity, was particularly noteworthy, and the Taits acknowledged that it initiated their own work. A senior clinician at the Middlesex Hospital, B. Lewis, drew attention to the Dorfman study, and in 1952 Sylvia Simpson and James Tait, together with Helen Grundy, devised another bioassay that measured the effects of steroids on the excretion of isotopically labelled sodium and potassium.

This assay was first applied to steroid extracts of human urine, but in 1952 Grundy, Simpson and Tait turned their attention to a bovine adrenal extract produced and generously donated by Allen and Hanbury, UK. From this was obtained the so called "amorphous fraction", the apparently uncrystallisable but biologically active residue from adrenal gland extracts. This was the source of aldosterone.

In the 1950s, the major activity of international endocrinology was centred in the United States. None the less there were major British and European contributions relevant to biological science in general and the Taits' discovery of aldosterone in particular. Among the many substantial and enduring contributions was the invention of partition chromatography by A.J.P. Martin and R.L.M. Synge, for which they received the Nobel Prize for Chemistry in 1952. This technology was applied in paper chromatographic systems to the analysis of steroids by the remarkable Ian Bush, another of the scientific prodigies of the era, at the MRC's laboratories in Mill Hill. This was a splendid achievement, and central to the aldosterone story.

In the early 1950s a major competition had developed between Sylvia Simpson and Jim Tait at the Middlesex Hospital and two American groups, in the race to find the mineralocorticoid still missing from the known portfolio of adrenal steroid hormones. The Taits' advantages were considerable: not only were they able to use the recently available radioisotopes of sodium and potassium to develop the most sensitive bioassay for mineralocorticoid activity, but also the Bush chromatographic methods, which enabled them to isolate a fairly pure sample of the hormone.

Then, with their colleagues, crucially including Tadeus Reichstein, the Nobel Laureate chemist at CIBA, the structure of aldosterone was determined, and the race was won. This was an outstanding achievement in international terms for the Taits and for British science – the direct result of the coming together of a team whose combined technical skills were necessary for success. The collaboration between Jim and Sylvia Tait became a lifelong association that generated outstanding research on steroids, especially in the aldosterone field that they dominated for over 35 years. Both the Taits were elected Fellows of the Royal Society in 1959.

A little later, Sylvia and Jim Tait were head-hunted by Gregory Pincus, of contraceptive-pill fame, and in 1960/61 they joined the staff of the Worcester Foundation of Experimental Biology and Medicine in Shrewsbury, Massachusetts, as senior scientists. The attraction of working in an institution where a critical mass of the staff were interested in steroids, and which at that time was at the height of its international scientific impact, was clearly irresistible.

The achievements of the 10 years at the Worcester were considerable, and it was there that the husband-and-wife team developed new methods for studying hormone dynamics, secretion rates and rates of metabolism, again using newly available radio-isotopically labelled products, which by this time included the steroids themselves. They also developed an isotopic method for the estimation of aldosterone concentrations in peripheral blood, which, falling as they do within the picomolar range, was again a considerable technical achievement, before the development of the immunoassays that now make such measurement routine.

Sylvia and Jim Tait returned to the UK in 1970, as co-directors of the Biophysical Endocrine unit at the Middlesex Hospital Medical School, London University, where Jim was appointed Professor of Physics as Applied to Medicine. There they continued research on the cellular functions of the adrenal cortex, with particular emphasis on the mechanisms of regulation of secretion of the different hormone types.

In 1982 Sylvia and Jim retired to the New Forest in Hampshire, where together they greatly enjoyed every aspect of living in the country. In a way, their domestic roles mirrored their laboratory division of labour: he was the great knowledgeable wine master and she the accomplished chef. However, Sylvia retained her avid interest in science, and had many friends and colleagues in science around the world. But, above all, it was to her husband and to their joint research activity that her unwavering loyalties remained as strong as ever, to the end.

John P. Coghlan and Gavin P. Vinson