Christian René Marie Joseph, Viscount de Duve (2 October 1917 – 4 May 2013) was a Nobel Prize-winning Belgian cytologist and biochemist.

[2] In addition to peroxisome and lysosome, he invented scientific names such as autophagy, endocytosis, and exocytosis on a single occasion.

[3][4][5][6][7] The son of Belgian refugees during the First World War, de Duve was born in Thames Ditton, Surrey, England.

His thesis earned him the highest university degree agrégation de l'enseignement supérieur (equivalent to PhD) in 1945.

He went for further training under (later Nobel Prize winners) Hugo Theorell at the Karolinska Institutet in Stockholm, and Carl and Gerti Cori at the Washington University in St. Louis.

In 1974, the same year he received his Nobel Prize, he founded the ICP, which would later be renamed the de Duve Institute.

[15] He wanted to specialize in endocrinology and joined the laboratory of the Belgian physiologist Joseph P. Bouckaert, whose primary interest was one insulin.

[16] However, laboratory supplies at Leuven were in shortage, therefore he enrolled in a programme to earn a degree in chemistry at the Cancer Institute.

The book was condensed into a technical dissertation which earned him the most advanced degree at the university level agrégation de l'enseignement supérieur (an equivalent of a doctorate – he called it "a sort of glorified PhD") in 1945.

In 1947, he received a financial assistance as Rockefeller Foundation fellow and worked for six months with Carl and Gerti Cori at Washington University in St. Louis (the husband and wife were joint winners of The Nobel Prize in Physiology or Medicine in 1947).

[19] In March 1947 de Duve joined the faculty of the medical school of the Catholic University of Leuven teaching physiological chemistry.

In 1960, Detlev Bronk, the then president of the Rockfeller Institute (what is now Rockefeller University) of New York City, met him at Brussels and offered him professorship and a laboratory.

Since 1921, insulin was the first commercial hormonal drug originally produced by the Eli Lilly and Company, but their extraction methods introduced an impurity that caused mild hyperglycaemia, the very opposite of what was expected or desired.

He and de Duve soon discovered that the HG factor was synthesised not only by the pancreas but also by the gastric mucosa and certain other parts of the digestive tract.

The pair's work showed that glucagon was the major hormone influencing the breakdown of glycogen in the liver—the process known as glycogenolysis—by which more sugars are produced and released into the blood.

[37] De Duve's original hypothesis that glucagon was produced by pancreatic alpha cells was proven correct when he demonstrated that selectively cobalt-damaged alpha cells stopped producing glucagon in guinea pigs;[38] he finally isolated the purified hormone in 1953,[39] including those from birds.

[40][41][42][43] De Duve was first to hypothesise that the production of insulin (which decreased blood sugar levels), stimulated the uptake of glucose in the liver; he also proposed that a mechanism was in-place to balance the productions of insulin and glucagon in order to maintain normal blood sugar level, (see homeostasis).

To their surprise the enzyme activity was increased back to that of the fresh sample; and similar results were replicated every time the procedure was repeated.

[51] That same year, Alex B. Novikoff from the University of Vermont visited de Duve's laboratory, and, using electron microscopy, successfully produced the first visual evidence of the lysosome organelle.

After the confirmation of lysosome, de Duve's team was troubled by the presence (in the rat liver cell fraction) of the enzyme urate oxidase.

He presented his discovery at a meeting of the American Society for Cell Biology in 1955,[57] and formally published in 1966, creating the name peroxisomes for the organelles as they are involved in peroxidase reactions.

[59][60] De Duve and his team went on to show that peroxisomes play important metabolic roles, including the β-oxidation of very long-chain fatty acids by a pathway different from that in mitochondria; and that they are members of a large family of evolutionarily related organelles present in diverse cells including plants and protozoa, where they carry out distinct functions.

According to de Duve's version, eukaryotic cells with their structures and properties, including their ability to capture food by endocytosis and digest it intracellularly, developed first.

[63] De Duve proposed that peroxisomes, which allowed cells to withstand the growing amounts of free molecular oxygen in the early-Earth atmosphere, may have been the first endosymbionts.

[68][69] However, de Duve believed that "Most biologists, today, tend to see life and mind as cosmic imperatives, written into the very fabric of the universe, rather than as extraordinarily improbable products of chance.

He had been long suffering from cancer and atrial fibrillation, and his health problems were exacerbated by a recent fall in his home.

[84] De Duve was one of the founding members of the Belgian Society of Biochemistry and Molecular Biology, established on 15 September 1951.