TORONTO - Actress Shirley Douglas was on the set of "Degrassi: The Next Generation" for a guest appearance Thursday - although she admits she didn't know until recently that the show was still in production.

Douglas said she was surprised when she got the invitation to appear on the wildly popular teen show. "I used to watch Degrassi a long time ago, and I didn't realize they're still making it, because I don't have any children at home and I don't watch a lot of television for young people," Douglas said in an interview.

"So I was very excited when I heard they were still doing it."

The 73-year-old Toronto-based actress - who has appeared in such iconic Canadian TV shows as "Road to Avonlea," "Wind at My Back," "Robson Arms" and "Corner Gas" - has a role as head of the theatre department at a college that one of the "Degrassi" characters has applied to.

She said she thinks of "Degrassi" as a Canadian icon.

"It's exciting that this company has stayed together and kept going quite successfully," she said.

"This show has been going a long time and it runs beautifully, it just runs beautifully."

Mike Lobel, who plays Jay Hogart on the show, appears in one scene with Douglas. He said he was intimidated to meet her but immediately felt comfortable.

"The first thing about Shirley that I think you realize is that she has this very open personality and she'll talk about anything. She knows tons about everything and she's really just the coolest person to listen to," said Lobel.

"It was nerve-racking to meet her, though," he added. "She's just so commanding. She's a commanding woman, a very commanding actress, and she makes you pay attention."

While Douglas has been asked to star in just one "Degrassi" episode so far, she said she certainly wouldn't turn down the opportunity to make her character a recurring one.

"I would love to have her keep coming back to the school," she said.

Douglas has also starred in several films, including "The Stone Angel," "Anne of Green Gables" and "Who's Afraid of Virginia Woolf."

Born to storied politician Tommy Douglas in Weyburn, Sask., in 1934, Douglas was married to actor Donald Sutherland and is the mother of "24" star Kiefer Sutherland.

The episode will air in January 2008.