Nicolae Constantin Paulescu: the first explicit description of the internal secretion of the pancreas

The purpose of this article is to describe the research of Nicolae Constantin Paulescu and to emphasize his role in the discovery of insulin.

We made a thorough review of the literature and research in the Romanian Academy Archive in order to find adequate references.

In 1912 N.C. Paulescu analysed the clinical and biochemical alterations in diabetic patients and in dogs after performing a pancreatectomy, that apart hyperglycemia and glycosuria (carbohydrate metabolism), had noted also changes in lipid and protein metabolism. In 1916 he started the experiments with a pancreas extract obtained by his original method, that was injected intravenously to the diabetic dogs. The results of his first experiments showed: "The pancreatic extract injected into a peripheral vein produce: 1) A diminution and even a temporary suppression of diabetic hyperglycemia, which may be replaced by hypoglycemia; 2) A diminution or even temporary suppression of glycosuria; 3) A diminution of blood urea; 4) A diminution of urinary urea. In other words, the intravenous injection of the pancreatic extract has as effect the disappearance of diabetic symptoms. The attenuation of the diabetic syndrome begins immediately after the injection. It reaches a maximum after 2 hours,- and it lasts for about 12 hours". He concluded as such: "This discovery,- which sheds a bright light over the pathogenesis of diabetes gives us also the key for the treatment of this syndrome". In 1921, Paulescu had published extensively his data in two outstanding French journals 8 months before the first publication of Banting and Best from February 1922. It is clear that insulin has been discovered in Europe.

Paulescu thought that a new hormone - Pancreine, that he discovered is the key element in the treatment of diabetes, but his outstanding research was unfairly neglected.