Neuroendocrine responses regulating susceptibility and resistance to autoimmune/inflammatory disease in inbred rat strains.

Rodent animal models of inflammatory and autoimmune disease have been important tools in the study of the interaction between neuroendocrine physiology and the immune responses. The rat has been particularly useful in part because, in contrast to other species, most rat models of autoimmune/inflammatory disease are induced rather than spontaneous. This allows for systematic and controlled manipulations of the neuroendocrine system in relation to exposure to the antigen or proinflammatory trigger. The most frequently used immune challenges include lipopolysaccharide-induced septic shock, carrageenan-induced local inflammation and adjuvant or bacterial cell wall-induced arthritis. By analyzing the responses to these challenges in different strains of rats and mice it has been possible to define the relationships between the neuroendocrine and immune systems and to identify some mechanisms through which these connections confer susceptibility and resistance to autoimmune and inflammatory diseases. The present review will discuss data obtained from rodent physiology, indicating that an important component in the susceptibility or resistance to development of these diseases is due to dysfunctional regulation of the immune response by the neuroendocrine hypothalamic-pituitary-adrenal axis. In particular, the importance of neurons of the paraventricular hypothalamic nucleus in determining susceptibility or resistance to autoimmune and inflammatory disease will be discussed.