Gantlet, written in early modern English as gantlope, refers to a form of military punishment in which an offender runs between two assaulting rows of soldiers. The word evolved into gantlet likely from the influence of the far more common gauntlet, which refers to gloves. Thus the idiomatic expressions were to run the gantlet and to throw down the gauntlet.
However, gauntlet has been favored in place of gantlet for over two centuries: to run the gauntlet has, since the 1700s, been far more common in written English than the original phrase. To continue using gantlet is thus to confuse readers who, by now rightfully, assume you misspelled gauntlet. Consider gantlet obsolete.