Stress-induced glucocorticoid elevation is a highly conserved response among vertebrates. This facilitates stress adaptation and the mode of action involves activation of the intracellular glucocorticoid receptor leading to the modulation of target gene expression. However, this genomic effect is slow acting and, therefore, a role for glucocorticoid in the rapid response to stress is unclear. Here we show that stress levels of cortisol, the primary glucocorticoid in teleosts, rapidly fluidizes rainbow trout (Oncorhynchus mykiss) liver plasma membranes in vitro. This involved incorporation of the steroid into the lipid domains, as cortisol coupled to a membrane impermeable peptide moiety, did not affect membrane order. Studies confirmed that cortisol, but not sex steroids, increases liver plasma membrane fluidity. Atomic force microscopy revealed cortisol-mediated changes to membrane surface topography and viscoelasticity confirming changes to membrane order. Treating trout hepatocytes with stress levels of cortisol led to the modulation of cell signaling pathways, including the phosphorylation status of putative PKA, PKC and AKT substrate proteins within 10 minutes. The phosphorylation by protein kinases in the presence of cortisol was consistent with that seen with benzyl alcohol, a known membrane fluidizer. Our results suggest that biophysical changes to plasma membrane properties, triggered by stressor-induced glucocorticoid elevation, act as a nonspecific stress response and may rapidly modulate acute stress-signaling pathways.

This study addresses the uneasiness that public relations (PR) professionals are experiencing regarding word-of-month (WOM) communication and the growing phenomenon of electronic WOM. That uneasiness is based on the notion that companies and brands no longer control their message. Instead, consumers, who communicate with other consumers, have seized control. However, this study indicates that companies and brands can retain some control of the message if they properly engage their consumers. While eWOM communication is growing and evolving, this study finds that consumers remain skeptical about eWOM messages. They crave supporting information before deciding how to act or behave. This is where PR professionals come into play. If they can successfully engage their consumers and interact with them through avenues such as social media, they can be effective in influencing eWOM communication. The study finds that persuasive eWOM communication requires supporting evidence. It is the PR professional's responsibility to provide information that can influence the eWOM communication about their product. Several tactics outlined in this study can help PR professionals accomplish this objective.

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