About ASN

Floyd C. Rector, Jr., MD

January 15, 2023

Leaders in all branches of human endeavor enhance their environs and erect new edifices to provide new paths and portals for those who follow. For nephrology in the second half of the 20th century, Floyd Rector was such a leader, using his rare intellectual gifts and creative insights to forge major new advances in basic and clinical kidney research. Dr. Rector, the 11th president of the American Society of Nephrology (ASN), died on January 15, 2023, just 13 days shy of his 94th birthday.

Floyd Clinton Rector Jr. was born and raised in the small town of Slaton in West Texas, where he attended nearby Texas Tech University and earned a B.S. degree with honors in 1950. He then went on to Dallas and the fledgling University of Texas Southwestern Medical School, graduating with the M.D. degree, again with honors, in 1954. It was here that he garnered the attention and respect of Dr. Donald W. Seldin, Chairman of the Department of Medicine, who would go on to mentor his exceptional student through the next two years of medical residency training, arrange for him to receive intensive research training in renal acid–base physiology at National Institutes of Health, and then encourage him to return to Dallas in 1958 to establish the program that over the next 15 years would prove to be one of the world's most productive schools for basic and clinical renal research.

In 1973, Floyd accepted an offer from Dr. Holly Smith, Chair of Medicine at the University of California, San Francisco, to serve as Professor and Director of the Division of Nephrology. The next 16 years saw stunning discoveries of mechanisms and regulation of tubule ion transport, urinary acidification, and urinary concentration and dilution, among many other areas discussed in further detail below. Once again, Floyd Rector created a worldclass research environment for exploration of mechanisms of kidney function and regulation in health and disease.

From 1989 until his retirement in 1995, Dr. Rector took on an administrative role as Chair, Department of Medicine. He proved to be a warm and popular leader and mentor, not only to students but to younger faculty forging their own independent careers as investigators and clinical scholars. Throughout his careers in Dallas and San Francisco, Floyd greatly enjoyed bedside teaching of medical students, residents, and clinical fellows. As with his mentor, Dr. Seldin, these rounds usually involved a highly cerebral dissertation on nephron ion transport regulation to explain the underlying cause of a patient's particular fluid and/or electrolyte disorder, with the patient and many of the surrounding medical team agog and bewildered by the onslaught of uncommon erudition. Dr. Rector was generally considered to be a demanding but gentle interrogator of those surrounding him, traits also recognized by those in the Rector laboratory where daily research findings were also usually dealt with in a rigorous yet cordial manner. In recognition of these qualities Dr. Lee Goldman, Dr. Rector's successor as Department Chair at University of California, San Francisco, established an annual Floyd C. Rector, Jr. Residency Research Symposium designed to highlight the scholarly work of students and residents in areas of basic and clinical investigation as well as innovations in delivery of medical care. For many years into his retirement, Floyd was a regular and devoted attendee and speaker at these annual meetings.

Much of Dr. Rector's research effort in Dallas focused on mechanisms of renal ion transport contributing to Extracellular fluid volume and acid–base balance and imbalance. James Clapp and Floyd Rector demonstrated active chloride transport in the distal nephron. Rector, Seldin, and Norman Carter further showed that bicarbonate reabsorption and proton secretion in proximal and distal tubules could best be explained by hydrogen ion secretion across the apical membrane, rather than direct bicarbonate reabsorption, as evidenced by acid disequilibrium pH during carbonic anhydrase inhibition. Under Dr. Rector's direction, numerous clearance and micropuncture studies involving Jaime Herrera, Manny Martinez-Maldonado, Felix Brunner, Wadi Suki, Neil Kurtzman, Roland Blantz, among others, explored mechanisms of tubule fluid reabsorption in the regulation of body fluid balance. In collaboration with Juha Kokko, Dr. Rector identified the ion transport properties of isolated and perfused segments of rabbit thin limbs of Henle, which inspired creation of a unique biological model of the countercurrent multiplication system devoid of active solute transport to explain how urine is concentrated. John Fordtran, soon to be recognized as a renowned gastroenterologist, collaborated closely with Dr. Rector to perform classical studies of solute and water absorption across discrete segments of small intestine in normal human subjects as well as those with various forms of malabsorption.

In San Francisco, Dr. Rector's new team, including Robert Alpern, Martin Cogan, David Warnock, and Christine Berry, showed that the removal of bicarbonate from luminal fluid produced concentration gradients that secondarily drove the passive reabsorption of chloride. Dr. Rector also led the effort to define the sodium and hydrogen transport systems in the proximal tubule, identifying a sodium–hydrogen exchanger and a proton ATP-ase. In addition, the team discovered a coupled carrier whereby two bicarbonate ions and one sodium ion move simultaneously across the basolateral membrane, driven by the lumen negative electrical potential, without the need for additional active transport.

Dr. Rector collaborated with clinical researchers Drs. Anthony Sebastian and Morris Schambelan in translating concepts derived from bench research to designing and executing meticulous metabolic balance studies to account for the findings in a patient with hyperkalemia, hyperchloremic metabolic acidosis, and resistance to aldosterone. Following sodium sulfate (a nonreabsorbable anion source) rather than sodium chloride infusion into the patient revealed an underlying defect of increased chloride permeability in the distal nephron. The finding inspired proposal of the concept of a "chloride shunt" whereby dissipation of the distal tubule electrical potential difference interferes with potassium secretion and augments sodium reabsorption, giving rise to the phenotype of type II pseudohypoaldosteronism with hyperkalemia and hypertension. Richard Lifton and coworkers at Yale subsequently demonstrated that with no lysine [K] kinase mutations in the distal tubule resulted in gain-of-function of this chloride shunt, establishing a molecular genetic basis for the electrolyte disturbances observed in this disorder. Such give and take between bench and bedside encouraged Dr. Rector's basic science and clinical teams to approach other more common clinical disorders, including metabolic acidosis and alkalosis, hyperkalemia and hypokalemia, and disorders of calcium homeostasis, among many others.

Floyd Rector led two outstanding laboratories that delved deeply into challenging questions in renal biology and medicine. His clinical associates shared his passion for applying basic science concepts to problems of fluid and electrolyte homeostasis. Both spheres attracted dozens of bright young minds for fellowship training under his tutelage, their names too numerous to recount here. Suffice it to say that many have gone on to highly successful careers in academia, biotechnology, and clinical practice. With them more than 150 original, peer-reviewed papers saw publication in the most respected scientific journals.

Floyd was a visiting professor at many institutions. He served on many editorial boards and was elected to the most respected academic societies. Among his many prestigious awards were the Homer Smith Award of ASN in 1982, Distinguished Texas Tech Alumnus Award in 1987, Mayo Soley Award of the Western Society for Clinical Research in 1990, Donald W. Seldin Award of the National Kidney Foundation in 1996, establishment at University of Texas Southwestern of two Floyd C. Rector Jr. Endowed Chairs (in Nephrology in 2001 and Medicine in 2003), the A.N. Richards Award of the International Society of Nephrology in 2001, and the Robert W. Berliner Award of the American Physiological Society in 2002. He served as president of the ASN from 1976 to 1977 and councilor of the International Society of Nephrology from 1978 to 1985.

One afternoon in the spring of 1973, soon after Floyd arrived in San Francisco, we met at my home in Mill Valley at the invitation of the W.B. Saunders medical book publishers to design and organize a new and comprehensive textbook of the kidney, including basic anatomy, physiology, biochemistry and molecular biology, pathophysiology, pathology, and the diagnosis and treatment of renal disease. With wonderful canapés prepared by my wife Jane, accompanied by a full-bodied and well-aged Napa Valley Cabernet Sauvignon, we spent 4 hours laying out a blueprint of five sections and 44 chapters authored by nearly 100 highly respected experts. Thirty months later saw the release of the First Edition of Brenner and Rector's "The Kidney." Floyd joined in editing the next three editions, while the textbook secured a strong worldwide reputation among students, residents, fellows, established renal scientists, and practitioners of nephrology, urology, internal medicine, and pediatrics. For Floyd's invaluable vision, guidance, and encouragement over those four editions, the next (fifth) edition was dedicated to him in honor of his splendid service. Now 50 years since the original Brenner and Rector was designed, our shared legacy continues with the 12th edition currently in production, ably led by six of my former associates.

Floyd Rector leaves in the memories of his family, friends, and associates a bounty of recollections of a warm, courteous, and generous man. He was among the greatest in his profession in the 20th century, but despite this well-earned distinction, he neither sought nor expected an audience. Instead he devoted himself to his wife Marge of 69 years; their daughters Lynn, Ruth, and Janet; four loving grandchildren; and six adored great grandchildren. Marge and Floyd shared a beautiful home in Sausalito, CA, overlooking Angel Island in San Francisco Bay, where they enjoyed their sailboat, and they were active golfers and tennis players. Floyd also enjoyed giving classical guitar performances for family, friends, and guests. Marge was an accomplished and successful artist working in her architect-designed studio in nearby Woodacre until her death in 2019.

From these few fine threads that have been teased from the glorious tapestry that was Floyd Rector's life, we can readily discern his special virtues of high intelligence, creativity, undistracted focus, and his warmth and generosity. Long after his tapestry turns to dust, his contributions to science and medicine will not only endure but also continue to provide opportunity and direction for generations of successors. And for those of us fortunate to have known him personally, our tapestries will have become more storied, vibrant, and enlarged.