Bergstrom, Sune Karl (1916-2004), a Swedish biochemist, shared the 1982 Nobel Prize in physiology or medicine with fellow Swede Bengt Samuelsson, and with John Vane of the United Kingdom. The three men received the prize for discoveries about prostaglandins and related substances. Prostaglandins are substances resembling hormones. They play a role in a variety of functions, including reproduction, metabolism, allergic reactions, nerve-impulse transmission, muscle contraction, and blood pressure regulation. See Prostaglandin.