By Peter Castro
May 15, 1995 12:00 PM

WHEN JOEY LAWRENCE, THE teen idol from Blossom, made a guest appearance earlier this season on NBC’s John Larroquette Show, his character fell for sexy nurse Catherine Merrick, wittily played by Alison LaPlaca. “Wow!” Lawrence said at one point to LaPlaca. “You’re funny too!” Seizing the moment, LaPlaca, the undaunted survivor of too many canceled television series, shot back, “I know. It’s hard to believe I’ve been on five sitcoms that bombed; nobody gets me. That’s why I became a nurse.”

Curled up in her dressing room, LaPlaca, 35, recalls the live audience’s reaction. “Thank God they laughed,” she says. “At least they know I’ve been on other shows before.”

True, but they would be hard-pressed to remember the names on LaPlaca’s list of losers. For the first time in her bumpy career, LaPlaca, who joined the cast of Larroquette this season, finds herself on a show that seems a good bet to be renewed. She feels comfortable, she says, playing the star’s sassy girlfriend. “This show has no dogs or kids,” she says. “I don’t mean to minimize the wife role, but I like being the independent career woman.”

LaPlaca’s personal life has settled down too. The actress has been happily married for three years to actor-turned-director Philip Charles MacKenzie, 48. They worked together on 1988’s Brothers, on Showtime, in which she and MacKenzie both played gay characters, and in the 1989 Fox flop Open House, on which they were battling real estate agents. When they met in real life, she recalls, “it was a slow boil, and we just kept increasing the flame.” She sees MacKenzie as a stabilizing force. “I get aggravated and wound up,” she says. MacKenzie says it’s she who has the calming touch: “Alison just puts her hand on my face and kisses me.”

Those soothing qualities were sorely tested when the couple was caught in the cross fire of the Roseanne and Tom wars. In 1993, LaPlaca was hired to play a sitcom writer on ABC’s Arnold-driven The Jackie Thomas Show, which didn’t last a season. Her streak continued the following year on Tom, another Arnold bomb. MacKenzie, meanwhile, was directing episodes of Roseanne. When the Arnolds’ marriage went into meltdown, “we were Tom and Rosie central,” says LaPlaca. “People picked our brains. What could we tell anybody that the Arnolds hadn’t already revealed? We told them, ‘WatchHard Copy.’ ”

That should have been enough stress for any couple, but LaPlaca and MacKenzie were facing another, simultaneous struggle. MacKenzie, a nonsmoker, worried about her three-pack-a-day habit. She continued to smoke—until a doctor told her that, at the rate she was smoking, she would develop emphysema before she was 40. “We had a hellish time getting me under control,” recalls LaPlaca. “I felt like [Philip] was a parent yelling at me.” Ultimately, MacKenzie agreed to stop nagging. She quit cold turkey, she says, and hasn’t had a cigarette in more than two years.

What LaPlaca, who grew up in the wealthy Chicago suburb of Lincolnshire, Ill., could never give up on is performing. Her father, Peter, runs a saxophone manufacturing company, and by the time she was 6, LaPlaca was playing piano and singing show tunes for her older sisters Wendy and Laura, and her mother, JoAnne, a housewife. One of her high school classmates was Joe Lando, now on Dr. Quinn, Medicine Woman. “I was the wild child; she did everything right,” he recalls. The two are still pals. In 1982, LaPlaca graduated magna cum laude from Illinois Wesleyan University, where her drama teacher, John Ficca, remembers her as a star pupil. She won the lead in almost every production, he says, and “handled her success with wit.”

In 1983, LaPlaca moved to L.A., quickly winning bit parts on Cheers, Suzanne Pleshette Is Maggie Briggs and a couple of failed pilots. Four years later she landed her first steady TV job on Fox’s Duet, canceled in 1989. She rebounded with Open House, which was canceled a year later. Then came the two disastrous Tom Arnold shows and, finally, Larroquette. “I thought John was a real class act and the show was smart,” she says.

She should know. On the set LaPlaca is famous for her quick mind and rapid delivery. “I do have a pretty clipped tongue,” she admits. “So many men have come up to me and said I’m just like their ex-wife. That kills me.”