Choh Hao Li, the endocrinologist who discovered the human growth hormone and gave thousands of abnormally short children the chance for a more normal life, died Saturday in Berkeley, officials at UC San Francisco announced Tuesday. He was 74.
In more than 50 years of research in the University of California system, Li played a key role in the discovery of eight of the nine critical hormones produced by the pituitary gland, a pea-sized organ deep in the brain that regulates body growth, metabolism and fertility.
"Li's work at Berkeley was of major importance to endocrinology because he was one of the first chemists interested in isolating pituitary hormones and able to do it," said endocrinologist Roger Guillemin of the Salk Institute in La Jolla.
"He was also unusual in that he worked closely with biologists such as George Herbert Evans to understand their biological function," Guillemin said.
Among the hormones Li discovered were the luteinizing hormone and the follicle-stimulating hormone, both of which show promise for use in birth control and regulating fertility, and adrenocorticotropic hormone (ACTH), the so-called stress hormone that was used to treat various diseases before the advent of synthetic steroid hormones.
One of his last major accomplishments was the discovery of beta-endorphin, the most powerful of the body's natural painkillers.
But the achievement for which Li is most likely to be remembered was the discovery in 1955 of the human growth hormone--which, as the name implies, stimulates the growth of children and adolescents. He then developed a method of isolating the hormone from human cadavers and purifying it so that it could be administered to children suffering from a form of dwarfism caused by a growth hormone deficiency.
At the program's peak in 1973, 82,500 pituitary glands were collected for treatment of about 3,000 children. The program subsequently declined because fewer autopsies were performed and fewer pituitaries were collected.
By 1971, he had determined the structure of the human growth hormone and synthesized it in small quantities. That feat paved the way for production of the hormone in genetically engineered bacteria, greatly expanding the supply. The product was approved for sale in October, 1985, and about 6,000 U.S. children are now receiving the hormone.
Born and educated in China, Li emigrated to the United States in 1935 for graduate study in chemistry at UC Berkeley. After receiving his doctorate in 1938, he joined the Berkeley staff and remained there until 1967, when he moved to UC San Francisco. He became a U.S. citizen in 1955.
Li is survived by his wife, a son and two daughters.