Franz Leydig

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Franz von Leydig (May 21, 1821 - April 13, 1908), also Franz Leydig, was a German zoologist and comparative anatomist. [1] [2]

Franz Leydig studied philosophy in Munich beginning in 1840, and from 1842, Leydig studied medicine at the University of Würzburg, with Franz von Rinecker.[1] Leydig attained a doctorate of medicine from Würzburg in 1847. He became an assistant at the Institute for Physiology under Albert von Kölliker. In 1855, he became an extraordinary professor and, in 1857, professor for Zoology and Comparative anatomy at the University of Tübingen, and in 1875, Franz Leydig became a professor at the University of Bonn until retiring in April 1887.[2] Franz von Leydig died on April 13, 1908, in Rothenburg ob der Tauber.[1]

The "Leydig cells" (with testosterone) are named after Franz Leydig, who discovered them in 1850.[1]

Contents

[edit] Life

Franz Leydig was born on May 21, 1821, in Rothenburg ob der Tauber (on the Tauber river).[1]

Of three children, Franz Leydig was the only son of his father Melchior Leydig, a Catholic and a minor public official, and his mother Margareta, a Protestant.[2] Leydig shared both his father’s Catholic religion and hobbies: his father was a keen gardener and beekeeper. Leydig himself recalled later that those childhood interests began his lifelong concern with botany and zoology.[2] At age 12, the boy acquired a simple microscope, which he used in the majority of his free time.[2]

Franz Leydig studied philosophy in Munich from 1840, and studied medicine at the University of Würzburg from 1842 under Martin Münz (1785-1848), Schenk, and Franz von Rinecker (1811-1883).[2] Leydig received a doctorate in medicine at Würzburg on August 27, 1847, becoming an assistant in the physiology department, teaching also histology and developmental anatomy under Rudolf Albert von Kölliker (1817-1905).[2] Leydig became prosector at the zootomic institution in Würzburg in 1848, qualified as a lecturer in 1849, and became extraordinary professor on May 9, 1855.[2] In the winter of 1850-1851, Leydig made a journey to Sardinia, where he became aware of the rich marine life that was to become the subject of some of his most important researches. That journey, coupled with his early preoccupation with microscopy, directed the course of his life’s work.[2]

In 1857 Leydig became full professor of Zoology and Comparative anatomy at the University of Tübingen, and he published his Lehrbuch der Histologie des Menschen und der Tiere: his main contribution to morphology.[2] In the Lehrbuch, Leydig reviewed the crucial developments in the history of histology, including the discovery and definition of the cell by Jan Evangelista Purkyne (1797-1869), Gabriel Gustav Valentin (1810-1883), and by Theodor Ambrose Hubert Schwann (1810-1882), who described the cell as a vesicle containing a nucleus in 1839.[2] Leydig paid further tribute to other contemporary anatomists, particularly Johannes Peter Müller (1801-1858) for his work on glands and emphasizing cellular doctrine for pathology.[2] Leydig’s book was published at the time of similar subjects - most notably Kölliker’s Handbuch der Gewebelehre des Menschen (1852) and Joseph von Gerlach’s (1820-1896) Handbuch der allgemeinen und speciellen Gewebelehre des menschlichen Körpers... (1848). The Lehrbuch, however, gives the best account of the growth of comparative microscopical anatomy in the two decades following Schwann’s discoveries.[2]

Leydig became professor of comparative anatomy at the University of Bonn in 1875, where he also became director of the anatomical institute, as well as, director of the zoological museum and the zoological institute.[2] He was later made Geheimer Medizinalrat.

Leydig was emerited on April 1, 1887 (becoming "professor emeritus"), retiring to his home town.[2]

Franz von Leydig died on April 13, 1908, in Rothenburg ob der Tauber, his birthplace.[1]

He had married Katharina Jaeger, the daughter of a professor of surgery at Erlangen, who survived him; they had no children.[2] During his lifetime, Franz Leydig was granted many honours, including personal ennoblement, and an honorary doctorate of science from the University of Bologna.[2] He was a member of several medical and scientific societies, including the Royal Society of London, the New York Academy of Sciences, and the Imperial Academy of Science of St. Petersburg.[2]

[edit] Impact

Franz von Leydig's work on neural tissue influenced the Norwegian zoologist and polar explorer Fridtjof Nansen (1861-1931), who along with Wilhelm His (1841-1904) and Auguste-Henri Forel (1848-1931), were the first to establish the anatomical entity of the nerve cell.[2]

The medical term "Leydig cells" (which can synthesize testosterone) are named after Franz Leydig, who discovered them in 1850.[1]

In addition to its historical importance, Leydig’s "Lehrbuch" is significant for his description of a large secretory cell, found in the epidermis of fishes and larvae amphibians.[2] The mucous cell is unusual in that it does not pour secretion over the surface of the epithelium; Leydig believed that the cell function was to lubricate the skin, and the cell now bears his name.[2]

Chief among Leydig's discoveries is the interstitial cell ("Leydig cells"), a body enclosed in a smooth endoplastic reticulum and holding lipid granules and crystals, which occur in the seminiferous tubules and the mediaseptum and connective-tissue septa of the testes.[2] The cells are believed to produce the male hormone testosterone. Leydig had described the interstitial cells in his detailed account of the male sex organs, "Zur Anatomie der männlichen Geschlechtsorgane und Analdrüsen der Säugetiere," published in 1850 (translated):

"The comparative studies of the testis resulted in the discovery of cells surrounding the seminiferous tubules, vessels, and nerves. These special cells are present in small numbers where they follow the course of the blood vessels, but increase in mass considerably when surrounding seminiferous tubules. These cells are lipoid in character; they can be colourless or can be stained yellowish, and they have light vesicular nuclei." -Franz Leydig, 1850[2]

The above description clearly indicates that Leydig recognized the specific morphology of those cells: only recently, have their endocrine nature and ultrastructure been fully understood.[2]

Leydig is also known for describing large vesicular cells that occur in the connective tissue and the walls of blood vessels in crustaceans in 1883: four different types of the latter have been determined.[2]

[edit] Notes

  1. ^ a b c d e f g "Franz von Leydig - Wikipedia" (German), German Wikipedia, 2006-10-29, de.wikipedia.org webpage: GermanWP-Franz_von_Leydig.
  2. ^ a b c d e f g h i j k l m n o p q r s t u v w x y "Franz von Leydig (whonamedit.com)" (biography), Ole Daniel Enerson, 2006, WhoNamedIt.com webpage: WNI-675-Leydig.

[edit] References

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