Two Swedes and an Englishman yesterday won the 1982 Nobel Prize in medicine for their pioneering studies of potent hormones that affect virtually every system in the human body, from fertility to circulation of the blood.

Drs. Sune K. Bergstroem and Bengt I. Samuelsson, both of the Karolinska Institute in Stockholm, which helps award the prestigious prize, and Dr. John R. Vane, of the British Wellcome Research Foundation Ltd., will share the $157,000 prize, the first of the Nobel awards to be announced this year.

Karolinska Institute faculty members assist in selection of prize winners. Bergstroem, who has long been considered a contender for the medicine prize, is chairman of the board of directors of the Nobel Foundation, which administers the award.

The three were cited for their discoveries concerning "prostaglandins and related biologically active substances," which are locally produced chemical messengers that function to defend cells against sudden changes caused by stress, trauma or disease.

The substances, which are named after their original discovery in the prostate gland, can have both positive and negative effects on the body.

The natural and synthetically produced prostaglandins--and drugs that counteract their effects--have a wide range of present and potential uses in medical treatment, in addition to the basic research leads offered by the discovery of a new biological system.

Experts say that future prostaglandin research may provide new avenues for treating the allergies that bother so many people, as well as a possible means for preventing heart attacks.

The Nobel committee noted that these chemicals are already used in obstetrics and gynecology, serving to induce both abortion and childbirth. The prostaglandins have also been used in the treatment of patients with circulatory system disturbances and peptic ulcers.

Compounds that inhibit the action of prostaglandins relieve pain caused by menstruation, gallstones and kidney stones.

Vane, 55, was cited for his "fundamental" discovery a decade ago that aspirin, one of the most common medications for treating pain and inflammation, acts by blocking the formation of prostaglandins and related chemicals. He is a former University of London professor who now directs group research and development at the pharmaceutical foundation.

Bergstroem, 66, who is regarded as the "father" of prostaglandin research dating to the 1950s, was credited with a "crucial breakthrough" in understanding the chemistry of these hormones. He showed that they are formed from common building blocks in unsaturated fatty acids.

Bergstroem is a professor of chemistry at the Karolinska Institute and chairman of the advisory committee on medical research of the World Health Organization.

Samuelsson, 48, is a former student of Bergstroem's who helped unravel the "biological significance" of the prostaglandin system and the various chemicals involved. He is chairman of the department of physiological chemistry and dean of the medical faculty of the Karolinska Institute.

Yesterday's award to three non-American scientists represented a break in the longstanding U.S. dominance of the world's most prestigious medical prize. Fifty-seven scientists from the United States have captured the prize--which is formally known as the Nobel Prize in Physiology or Medicine--since it was instituted in 1901.

Vane is the 20th British scientist to win the award, while Sweden now has a total of seven awards in this area, according to reports from Stockholm.

In 1977, the three won a prominent American prize, the Albert Lasker Basic Medical Research Award, which is often seen as a stepping stone to the Nobel Prize.

Yesterday, the three new Nobel winners were in Boston, part of a select group of researchers speaking at a scientific gathering celebrating the bicentennial of the founding of Harvard Medical School.

They celebrated the news of their awards by drinking champagne toasts to each other, expressing surprise and pledging to continue their work "as usual."

The recipients share a prize of 1.15 million kronor, which last year was worth $180,000 but this year is worth only $157,000 because of last week's 16 percent devaluation of the Swedish currency.