Psychological stress delays healing of physical wounds, a new study says.
Phillip Marucha, and his colleagues at the University of Illinois at Chicago in a study of laboratory mice, found that psychological stress, brought on by confinement, delayed the closing of wounds by more than 45 percent, reports science portal eurekalert.org.
A range of cell and genetic changes accounted for the slow recovery, it said.
"The cells that help remake tissue didn't differentiate the way they would have in normal animals. They didn't line up the way they were supposed to. And they didn't develop the tiny contractile fibres that help pull together the edges of the wound," Marucha said.
Marucha said stress launches a sequence of events that constrict blood vessels and deprives the tissues of oxygen.
"Expression of the gene that codes the protein for those fibres was impaired." However, when the animals received hyperbaric oxygen (oxygen at a greater pressure than atmospheric oxygen), the delay in healing was almost eliminated.
The researchers found that when animals were stressed, expression of the gene increased, presumably to help make more nitric oxide.
But when the animals received hyperbaric oxygen, gene expression returned to normal levels, suggesting that the nitric oxide levels necessary for healing had been restored by the increased tissue oxygen levels.