Background
Joseph-Louis Renaut was born on December 7, 1844, in La Haye-Descartes, Indre-et-Loire, France.
Joseph-Louis Renaut (1844-1917). Courtesy of the United States National Library of Medicine.
Collège de France, Paris, France
From 1869 until 1875 Renaut studied histology under Cornil and Ranvier at the Collége de France.
Collège de France, Paris, France
From 1869 until 1875 Renaut studied histology under Cornil and Ranvier at the Collége de France.
Louis-Antoine Ranvier (2 October 1835 – 22 March 1922) was a French physician, pathologist, anatomist, and histologist, who discovered the nodes of Ranvier, regularly spaced discontinuities of the myelin sheath, occurring at varying intervals along the length of a nerve fiber.
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1880
anatomist histologist physician scientist
Joseph-Louis Renaut was born on December 7, 1844, in La Haye-Descartes, Indre-et-Loire, France.
Renaut began his medical studies at Tours in 1864, continued them in Paris in 1866. From 1869 until 1875 he studied histology under Cornil and Ranvier at the Collége de France.
After completing his medical studies in Paris, in 1869 Renaut won the coveted position of interne des hôpitaux. He held this post until 1875.
Research never overshadowed Renaut’s devotion to medicine. He completed his medical thesis on erysipelas (Contribution á l’étude de l’érysipèle…, 1874), and passed the agrégation with his paper De l’intoxication saturnine… (1875), earning two silver medals. In 1876 he accepted the directorship of the pathological anatomy laboratories at the Charité Hospital in Paris.
Many scholars in the French educational establishment felt that defeat in the Franco-Prussian War was due to the superiority of German education and technology. The ensuing French educational reforms decisively affected Renaut. He became a répétiteur in Claude Bernard’s new histology laboratory at the Collège de France, dedicated by Ranvier, its director, to effective “competition with similar German establishments.”
In 1877 Renaut accepted the chair of general anatomy and histology at the new Medical Faculty of Lyons. which was created to emulate the German example of educational decentralization. He taught at Lyons for forty years and served as chief physician at the Croix-Rousse, Perron, and Hôtel-Dieu hospitals, retiring from clinical service in 1900.
Renaut’s research and writing focused on histology. In France, his Traité d’histologie pratique (1889–1899) was considered, together with Ranvier’s Traité technique d’histologie, as “the most important and original work on this science in the 19th century“(Mollard, “Le Professeur Renaut”). It emphasized comparative anatomy and revealed Renaut’s interest in embryology and developmental physiology.
Renaut's contributions to histology and pathology include the study of the fibrohyaline membrane (known as “Renaut’s layer”) between the corium and epidermis; the secretory function of connective tissue and the intestinal epithelium; the ciliary epithelium in the lung; the diapedesis of blood cells across the intestinal epithelium: and the continuity of the lymphatic capillary system.
He also investigated the syncytial nature of cardiac muscle fibers; the epithelial origin of neuroglia; the aggregation of lymphocytes to form lymphoid follicles: and the pathology of progressive muscular atrophy, of nephritis and myocarditis, and of the fibrous forms of tuberculosis in the lung.
Another Renaut's achievements included two silver medals that he received for his research titled De l’intoxication saturnine… (1875) and the directorship of the pathological anatomy laboratories at the Charité Hospital in Paris. He also founded the Revue générate d’histologie in 1904 and was one of the founding members of the Société de Dermatologie et de Syphiligraphie.
Renaut hypothesized that the faster development of muscle weakness in lead intoxication, as compared to progressive muscular atrophy, was due to the more severe muscle fiber atrophy and secondary myopathic changes (muscle fiber necrosis) in the former.
Quotations: "I have long sought an interpretation and I confess that I can find no other than the following: In adult animals advanced in age such as those sacrificed in the veterinary schools, the nerves constantly produced new interannular hyaline segments that vegetate in the periphery and replace the nerve elements whose evolution is completed."
Louis Renaut was a member of the Paris Academy of Medicine, the Société Anatomique, the Société de Biologic, and the Société de Dermatologie et de Syphiligraphie, which he helped found. He was also a member of the Revue générate d’histologie from 1904.
Renaut actively participated in many official functions at the University of Lyons and wrote poetry under the pseudonym Sylvain de Saulnay. Needless to say that one of his volumes "Ombres colorées" even won a prize from the French Academy.
