The concept of cellular "fight-or-flight" reaction to stress.

As animals respond to environmental stress with a set of default reactions described as the "fight-or-flight" response, so do epithelial and endothelial cells when they are confronting stressors in their microenvironment. This review will summarize a growing body of data suggesting the existence of a set of stereotypical cellular reactions to stress, provide some examples of diseases that are characterized by excessive flight reactions, describe the cellular mechanisms whereby the fight-or-flight reaction is accomplished, as well as cellular mechanisms triggering either fight or flight. It is proposed that cell-matrix adhesion is a sensitive indicator of the severity of stress. This indicator is interfaced with several default programs for cellular survival or death, thus dictating the fate of the cell. Some diagnostic and therapeutic applications of the concept, presently used and potentially useful, are outlined. The essential feature of this concept is its ability to categorize cellular events in terms of either type of default reaction, predict the details of each, and potentially exploit them clinically.