BRUSHING UP ON MANTOOTH

What's in a name? For Randolph Mantooth, who plays the mercurial Alex on ABC's Loving, the answer is simple: an unexpected career boost. The moniker of the '70s TV icon (remember Emergency?) is gaining him popularity in non-soap circles. Rock star Trent Reznor (of Nine Inch Nails) uses the name Mantooth when he checks into hotels. And Talk Soup's John Henson dropped Mantooth's name so often that the actor taped a series of cameo appearances for the popular cable show. ''At first I thought, 'Should I be insulted?' '' says Mantooth, 49. '' 'Is this what my career has come to?' But now I'm flattered.'' E! has also asked Mantooth to guest-host Talk Soup later this year. ''All because of my name,'' he says incredulously. ''You can't pay a publicist to get you this kind of attention. Is this a capricious business or what?''