HEIDENHAIN, RUDOLF

HEIDENHAIN, RUDOLF (1834–1897), German physiologist. Heidenhain, who was born in Marienwerder, was a convert to Christianity. He was appointed professor of physiology and histology at Breslau University in 1859. Heidenhain was considered one of the greatest of 19th-century physiologists; he laid the foundations for the recognition of the secretory mechanism as a system of intercellular physical and chemical processes. He described the active role of the kidney cells in the secretion of urine and proved that secretions, especially saliva, are products of the glands. This conception was based on his description of the cell structure of the salivary, mammary, gastric, intestinal, pancreatic glands, and in particular, of the histological changes in the glands while functioning. For this, he perfected histological methods, including one for staining the kidney cells, by the injection of indigo-carmine into the bloodstream. He started research into the mechanism of muscle contraction from the point of view of energetics and metabolism, paving the path for muscular physiology in later generations. His books include Mechanische Leistung, Waermeentwicklung und Stoffumsatz bei der Muskeltaetigkeit (1864) and Physiologie der Absonderungsvorgaenge (1880). His son MARTIN (1864–1949) was professor of anatomy at Tuebingen University and made important contributions to histology; he was one of the first cytologists. -BIBLIOGRAPHY: Bibliographisches Lexikon der hervorragenden Aerzte, 3 (1931), S.V. (Joshua O. Leibowitz)