Nobel Prize-winning pharmacologist James Black, whose breakthrough beta-blocker drugs help treat millions of heart patients and save thousands of lives, has died at age 85, his former university said Monday.

The University of Dundee in Scotland, which Black served as chancellor from 1992 to 2006, said the scientist died Sunday but gave few further details.

Black's discovery of the drugs propranolol and pronethalol _ which work by blocking the body's own response to stress hormones _ in the early 1960s revolutionized how doctors helped heart patients.

Dr. Clyde Yancy, the president of the American Heart Association, said the drugs' discovery was "one of the few things that really deserves the moniker: 'Landmark.'"

"Easily millions of patients have been helped with beta-blocking therapies," he said, adding that the family of drugs that grew out of Black's work remain "the standard of care" despite being discovered nearly half a century ago.

Beta-blockers are so called because they block beta receptors, one of two families of receptors present in organs such as the heart and the lungs. The receptors react to hormones such as adrenaline, so blocking them can have a calming effect on the heart muscle, insulating it from stress.

Studies have shown that the use of beta-blockers in heart attack patients dramatically decreased mortality rates, and drugs based on Black's work are still used to tackle a variety of other cardiac conditions, from abnormal heart rhythms to angina, anxiety, headaches and high blood pressure.

Although it's his work in the field of heart treatments for which he is best known, Black also made significant discoveries in the development of drugs to treat heartburn and ulcers.

He won the Nobel Prize for Medicine for his achievements in 1988 and was awarded Britain's Order of Merit _ a rare honor bestowed by the queen _ in 2000.

Black was the fourth of five children born in to what he described in an autobiographical sketch as "a staunch Baptist home" in Uddingston on the outskirts of the Scottish city of Glasgow. Awarded a scholarship to study at Scotland's St. Andrews University when he was only 15, Black applied himself to the study of medicine, meeting his future wife Hilary Vaughan at an undergraduate ball in 1944.

Saddled with debt after graduation, he spent three years teaching in Singapore, moving to London in 1950 with what he said was "no home, no income of any kind and no prospects whatsoever." But a chance meeting with an old colleague on Oxford Street led to a job with the University of Glasgow Veterinary School, where he said he "slowly learned, like a primitive painter, how to be an effective experimenter."

It was there that Black explored his interest in how to engineer the body's reaction to hormones. Convinced by British pharmaceutical chemical company ICI, who gave him his own laboratory, Black went to work creating beta-blockers during what he would later remember as one of the most exciting periods of his life.

He would later help discover cimetidine, which turned peptic ulcers from a potentially life-threatening disease into a far more manageable condition.

In addition to his chancellorship at Dundee, Black has held a variety of other leadership posts, including at University College, the Wellcome Foundation, and King's College _ all in London. In an interview with Scotland's The Sunday Herald in 2004, Black, the son of a mining engineer, said that his main passion was "making tools."

"I call myself a pharmacological toolmaker," he said.

Yancy said those tools have proven particularly durable.

"There've been other drugs that have been as good, but nothing has stood out as being better," he said. "They really have stood the test of time."

The university said Black's funeral would be held next Monday at St. Columba's Church in London. Black's wife, Hilary, died in 1986.