Nicolae Constantin Paulescu was a Romanian physiologist, professor of medicine, and politician, most famous for his work on diabetes, including patenting pancreine. The "pancreine" was an extract of bovine pancreas in salted water, after which some impurites were removed with hydrochloric acid and sodium hydroxide. Paulescu was also, with A. C. Cuza, co-founder of the National Christian Union and later, of the National-Christian Defense League in Romania. He was also a leading member of the Iron Guard.

Insulin is a peptide hormone produced by beta cells of the pancreatic islets encoded in humans by the insulin (INS) gene. It is the main anabolic hormone of the body. It regulates the metabolism of carbohydrates, fats, and protein by promoting the absorption of glucose from the blood into cells of the liver, fat, and skeletal muscles. In these tissues the absorbed glucose is converted into either glycogen, via glycogenesis, or fats (triglycerides), via lipogenesis; in the liver, glucose is converted into both. Glucose production and secretion by the liver are strongly inhibited by high concentrations of insulin in the blood. Circulating insulin also affects the synthesis of proteins in a wide variety of tissues. It is thus an anabolic hormone, promoting the conversion of small molecules in the blood into large molecules in the cells. Low insulin in the blood has the opposite effect, promoting widespread catabolism, especially of reserve body fat.