The director of the National Institute on Aging is leaving this summer, which, unless some vacancies are filled soon, will open an eighth key position at the National Institutes of Health. Dr. Robert N. Butler will go to Mt. Sinai Hospital School of Medicine to start a gerontology department, possibly as early as July. Butler took office as the institute's first director in 1976 just as he won the Pulitzer prize for non-fiction for his book, "Why Survive? Being Old in America."

Five of the NIH's 11 institutes are without directors now--the institutes for neurology, child health, arthritis, heart and lung, and dental research. The division of research resources also has no chief, and there is no deputy director for science.

The holdup appears to be at the top: NIH has no director, and no one wants to fill the lower positions until the top one is filled. James Wyngaarden, an academic clinician and chairman of the Duke University Medical School, is expected to be named NIH director, but that appointment has been expected for more than a month and so far there hasn't been a peep out of the White House.

An NIH spokesman said he wasn't aware of any opposition to Wyngaarden, whose name was welcomed by researchers fearful that a political appointee would get the job of heading the world's largest biomedical research facility.