A man bitten by a highly poisonous Pakistani pit viper was in serious but stable condition in University Hospital Thursday.

William E. Haast, 78, 419 Wakara Way in Research Park, was apparently involved in handling research snakes when he was bitten Wednesday night, said John Dwan, a spokesman for University Hospital. Haast took himself to the hospital for treatment, but the poison control center lacked a sufficient quantity of antivenin to adequately treat him because of his allergies.The San Diego Zoo was contacted and agreed to send the needed antivenin, which was taken by helicopter to the airport. It appeared the helicopter was too late because America West Airlines flight 274 had left the terminal and was on its way to the runway for take off.

Daphne Dicino, an airline spokeswoman, said the pilot overheard tower conversation concerning the medication and suggested the helicopter bring the antivenin to the aircraft as it waited on the taxiway. The medicine was handed to the pilot through the cockpit window and the antivenin was on its way.

Dicino said the medicine was transferred to Flight 180 in Las Vegas and arrived in Salt Lake City at 1:50 a.m. Thursday.

"The pilot saw a way to help without inconveniencing the passengers and still being able to get the medicine where it was needed," Dicino said. It would have taken between 30 and 40 minutes to return to the terminal and pick up the antivenin. "This allowed us to help out and still service our passengers."

Dwan said additional antivenin is expected from another U.S. source Thursday. He said this is not the first time Haast has been bitten. "You have to realize that this is his job and these kinds of things happen."

Haast is director of the Miami Serpentarium Laboratories, a company that produces snake venom for use in research and in making antivenin serums.