Insulin
Nicolae Paulescu, a Romanian professor of physiology was the first to isolate insulin. He did that in 1916. He called it pancrein. He isolated it by developing a pancreatic extract which, when injected into a diabetic dog, proved to have a normalizing effect on blood sugar levels. He had to interrupt his experiments because of World War I. In early 1921 he wrote four papers about his work carried out in Bucharest and his tests on a diabetic dog. Later that year, he published an extensive paper on the effect of the pancreatic extract injected into a diabetic animal. The title was: "Research on the Role of the Pancreas in Food Assimilation", published 22 June 1921 by the "Archives Internationales de Physiologie",