Ewald R. Weibel

Ewald R. Weibel

Ewald Rudolf Weibel was born in Switzerland on March 5, 1929, the son of a typewriter mechanic. After the Cantonal College in Aarau — the school Albert Einstein had attended 50 years earlier — and Medical School in Zürich, graduating in 1955, he worked as assistant in the Institute of Anatomy studying the anastomoses between bronchial and pulmonary arteries in the human lung in a physiological perspective, followed by a postdoc at Yale on this topic. In 1959 Andrè Cournand recruited him to Columbia University’s Cardiopulmonary Laboratory to “do anything on the structure of the lung that is of interest for physiology”. In this environment he identified morphometry, the quantitative study of structure, as the missing link between structure and function. He developed, with Domingo Gomez, a model and method for estimating a theoretical value of pulmonary diffusing capacity from first principles. This required electron microscopy; while doing this at Rockefeller Institute with George Palade he serendipitously discovered specific organelles of endothelial cells that serve clotting, now called Weibel-Palade bodies.

In 1963 he returned to Zürich, and in 1966 he became Chairman of the Institute of Anatomy at the University of Bern. Here he further developed the methods for morphometry, mainly stereological methods, to be applied at all levels of the body, from the lung to the membrane system of cells, particularly mitochondria. The study of lung structure in the perspective of gas exchange function led to the estimation of diffusing capacity in the human lung and in a wide range of mammals with different oxygen needs, large and small, athletic and more sedentary. The improvement of lung preparation techniques led to the discovery of the structure of the surfactant system, and allowed the study of the structural basis of lung mechanics, as well as the study of pulmonary oxygen toxicity and ARDS,

In 1975 he joined up with C. Richard Taylor from Harvard University in a collaborative project of comparative physiology and morphometry, now considering the entire respiratory system, from the lung through the circulation to the muscle mitochondria, what they called the pathway for oxygen, considering also the supply of fuels to the energetic processes. In the 20 years of their collaboration, until Taylor’s premature death, they oriented their studies on the hypothesis of symmorphosis that postulates economic design: there should be enough but not too much. The study of wild mammals of a large size range, combined with the comparative study of well-trained athletic animals with more sedentary species, supported the hypothesis of symmorphosis.

The research work of 60 years resulted in about 400 papers and was summarized in four books: “Morphometry of the Human Lung” 1963, Springer/Academic Press; “Stereological Methods” 1979, Academic Press; “The Pathway for Oxygen” 1984, Harvard University Press; “Symmorphosis” 2000, Harvard University Press.