Japan's Yoshinori Ohsumi has won the 2016 Nobel Price for groundbreaking experiments with yeast which exposed a key mechanism in the body's defenses where cells degrade and recycle their components.

He told Kyodo News Agency he was "extremely honored" to get the prize.

"He (Ohsumi) seemed surprised. The first thing he said was 'Aaah,'" said Thomas Perlmann, the Nobel Committee Secretary. "I think he was actually not maybe expecting this and he was surprised but very pleased and asked if he was allowed to leave the building and, of course, I explained that he would expect a lot of phone calls. I think he was very, very pleased so it was very nice to talk to him."

The Physiology or Medicine Prize is the first Nobel Prize awarded each year, and is worth $933,000.