Rat tracheal epithelial responses to water avoidance stress

Abstract

Psychologic stress has major effects on many organs and cellular systems. The hypothalamic-pituitary-adrenal axis, corticotropin-releasing factor (CRF), mast cells, and nerves have all been shown to be involved in intestinal epithelial responses to stress. There has been little information in the literature on stress and the lung. To investigate Wistar rat tracheal epithelial responses to acute water avoidance stress (1 hour). Tracheal tissue was examined in Ussing chambers. Increases in short-circuit current, but not in conductance, occurred after stress and were inhibited by previous injection of the CRF 1 and 2 receptor antagonist, alpha-helical CRF-(9-41). Electron microscopic morphologic evidence for tracheal mast cell activation and degranulation was found after stress. Stress and CRF injection both enhanced responses to substance P, but these effects were not inhibited by alpha-helical CRF. The data suggest that acute stress affects tracheal epithelium and sensitizes it to enhanced responses to substance P, partly through mast cell activation. Many but not all of these effects are mediated by CRF. These results offer the possibility that stress may be involved in inflammatory diseases of the lung such as asthma.