Carl Jacobj (Karl Jacoby)

Importance to Hirudotherapy

Johann Carl Jacobj (12 September 1857, Hamburg – 16 February 1944, Tübingen) belonged to the first generation of Oswald Schmiedeberg's pupils, the school through which experimental pharmacology spread from Strasbourg across the world. He studied medicine in Göttingen, Leipzig, Tübingen and Strasbourg, took his doctorate under Schmiedeberg in 1888, habilitated in pharmacology and toxicology in 1891, and after a brief period at the Imperial Health Office in Berlin held the chair of pharmacology at Göttingen from 1897 until his call to the newly founded pharmacological institute at Tübingen in 1907. His place in the history of hirudotherapy rests on hirudin. In 1884 John Berry Haycraft had shown, in Schmiedeberg's laboratory, that extracts of the medicinal leech inhibit blood coagulation. Jacobj and his Göttingen co-workers took the discovery up, named the active substance 'Herudin' or 'Hirudin' — the Göttingen hirudin work is recorded in the papers of his co-workers Franz (1903) and Bodong ('Über Hirudin', 1905) — obtained a patent on its preparation, and the substance was then sold commercially. Human therapeutic use was not contemplated at the time; hirudin's value lay in physiological experiments, where it kept blood uncoagulable — including in Jacobj's own organ-perfusion apparatus. More than half a century passed before hirudin was purified and its structure determined, and the early history with Haycraft and Jacobj was at times forgotten.