Stress is a factor in the healing of wounds, whether they be in skin or mucosal tissue, but stress affects healing in these tissues differently, according to new research conducted at the University of Illinois at Chicago.

"We believe what may improve healing in one tissue type may possibly worsen healing in a different type of tissue," says Christopher Engeland, assistant professor of periodontics at UIC. Engeland will present the findings March 5 at the American Psychosomatic Society's 67th annual meeting at the Chicago Downtown Marriott Hotel, 540 N. Michigan Ave.

In the new study, 65 UIC dental students received a small circular wound and a small longitudinal wound on the hard palate of the mouth at two different times: during the high-stress week of examinations, and during their relatively relaxed summer vacation.

The circular wound was videographed daily to monitor closure.

Biopsies from the longitudinal wound were taken 6 and 24 hours after wounding to assess the early and late stages of the inflammatory process, Engeland said. The levels of expression of eight genes involved in inflammation were determined from these biopsies.

The researchers found that wound closure was delayed during high stress. The stress of examinations was associated with a state of "hyper-inflammation" in healthy tissue and higher inflammatory responses in wounded tissue, Engeland said.

Previous studies showed that stress is associated with reduced inflammation in skin wounds, an effect that appears to be reversed in the mucosal tissue of the palate. The paradox suggests that attempts to improve healing by altering inflammation should be made in a tissue-specific manner, Engeland said.

"It is also interesting to note that the degree of inflammation in unwounded tissue was indicative of healing rates following injury," Engeland said. This suggests that healing rates might be predicted from the immune status in normal tissue prior to surgery, he said.