In an unusual exercise in White House press relations, Presidential press secretary Jody Powell summoned two United Press International reporters to his office Friday to complain about their story on alleged drug trafficking by Panamanian leader Omar Torrijos.

The story, which had been sent to newspapers around the country but not yet released for publication, was subsequently withdrawn by UPI and a another version was substituted.

Both versions of the story - part of a three-part series on the drug trafficking question and its relation to the new Panama Canal treaties - questioned administration handling of the allegations, which are the subject of a special closed Senate session today.

The incident points up the extent of the Carter administration's concern over the drug allegations and the damage they may do to chances for Senate ratification of the treaties.

According to one of the UPI reporthers, Cheryl Arvidson, Powell "attacked our integrity" at the meeting, "bluntly, flatly and with some degree of vigor." The four-hour meeting, she said, began with "two hours of shouting before they got to what they wanted to say."

Arvidson said Powell, "at one point in the meeting, lurched out of his desk, ran past me, and went out of his office, shouting that he couldn't deal with me, and slammed the door."

Powell said that "there was some heat exchanged" at the meeting. "It was a hot issue, and voices were raised on both sides.

"I kind of feel that people in the fourth estate are just like anybody else," Powell said. "Reporters have a perfect right to question the government, and ought to be questioned themselves. Integrity was not an issue, as far as I'm concerned."

If reporters "can't take the heat," he said, they "ought to be in another business."

UPI's substitute story is scheduled for publication today in a number of newspapers, including The Washington Star.

The same basic charges are included in both stories - including allegations that the White House tried to limit congressional access to classified documents, gathered over a 10-year period, referring to drug traffic and mentioning Torrijos and suggestions that some of the documents may have been removed from the files or destroyed.

The second version, however, contains some two dozen new paragraphs of administration rebuttal of those charges, along with previously unrevealed information on the Torrijos case supplied by the White House. The new story also notes, where applicable, that many of the damaging allegations came from second- or thirdhand sources, or from known treaty opponents in Congress.

Both Arvidson and Nicholas Daniloff, whose byline also appears on the story, said that the meeting did not result in a change in the substance of their story, and said they did not "feel that we were forced to change" it by including new information the White House supplied.

According to UPI Washington Bureau Chief Grant Dillman, who was also present at the meeting, he decided that "portions of [the original story] were unfair to the White House after hearing' Powell.

"I felt that our anonymous sources [in Congress] had given us information that was not borne out by on-the-record statements" made during the meeting, he said.

Phil Jordon special assistant to Attorney General Griffin Bell, said the administration objected to the "substance of the story, including insinuations and implications of an administration cover-up which were false."

Jordan, who has been handling the drug issue for the Justice Department and who was present at the Friday meeting, said the two UPI reporters had never "talked to me or to anyone involved, or indicated they even wanted to" before writing their story.

Another White House source said that the unusual step of disputing the story before it was published was justified because the canal treaties are "such a significant, major issue, and the implications of the charges were so severe." A story based on allegations made by "treaty opponents on the Hill," he said, was not responsible journalism.

According to Arvidson and Daniloff, they made a number of attempts to get the adminsitration's side before they wrote the story and received "very unsatisfactory answers" from both the Justice Department and the U.S. Drug Enforcement Administration.

Their questions dealt with DEA's movement of files on the drug allegations that had been requested by the Senate Intelligence Committee, and suggestions by unnamed, and occasionally second and third hand sources, that the administration had not fully responded to committee requests for information.

They also asked for information regarding the documents themselves, the reporters said, and were given a previously issued statement from the Justice press office saying that Torrijos has never been the "target" of a Justice investigation.