Corticotropin-Releasing Factor and Catecholamines: A Study on Their Role In Stress- Induced Immunomodulation
Frank Berkenbosch Free University, Amsterdam, Holland
Recently, there has been a growing body of interest in the interaction between stress, psychosocial factors, behavior, and the immune system. A major premise underlying this relationship is that stressors may increase vulnerability to certain diseases intimately connected with immunologic mechanisms such as infection, malignancy, and autoimmune disorders. However, as yet, no conclusive studies have been undertaken to prove the existence of this relationship. In fact, although many observations have been published demonstrating the immunosuppressive effect of chronic laboratory stressors in mammals (e.g., Keller, Weiss, Schleifer, Miller, & Stein, 1981, 1983), no detailed findings have been delineated to examine the relationship between immune parameters and the intensity, quality, and duration of stress. Moreover, although many in vitro studies have shown immunoregulatory potencies of stress-labile substances from neural and endocrine origin (e.g., Chang, 1984; Coffy & Hadden, 1985; Johnson, Smith, Torres, & Blalock, 1982), little evidence has been presented demonstrating the role of such substances in stress-induced changes in immunity in vivo. In this chapter, we review our studies on effects of acute stress on secretion of propiomelanocortin (POMC)-derived peptides from the pituitary gland and of catecholamines from the sympatho-adrenomedullary system. Moreover, we show that acute emotional stressors can enhance cellular and humoral immune responses and that neuroendocrine mechanisms are involved in these responses. In fact, our data favor the view that peptides derived from POMC, the production and release of which is controlled by hypothalamic corticotropin-releasing factor (CRF), may mediate enhanced immune response in acutely stressed animals.