Ortiz was arrested Monday morning on domestic violence charges at the Huntington Harbor, Calif., home he shares with Jameson and their twin sons.
He was released on $25.000 bail this afternoon.
A weeping UFC heavyweight champion said he never struck Jameson at a North Hollywood, Calif., press conference, and that a confrontation over the alleged drug abuse led to police being called.
"Jenna will be OK." Tito also said, "My parents have gone through addiction, and I'm not going to let my family go through that."
Ortiz said Jameson has been battling addiction to the painkiller for more than a year now, and that he and family members have been protecting her.
"Jenna and Tito have two children together, they planned on spending the rest of their lives together," Ortiz's attorney, Chip Matthews, said. "They want nothing more than to work together on this.
"For Tito and her family this has been an uphill battle. Unfortunately this morning she had a relapse," he said.
Ortiz and Jameson began dating after meeting on MySpace.com in 2006, shortly after she divorced Jay Grdina.
In January 2008, Jameson announced she was retiring from porn performing. She gave birth last year to Ortiz's twin sons, Jesse Jameson and Journey Jette.