OPIOID MEDIATED EFFECTS ON THE IMMUNE-SYSTEM - SYMPATHETIC NERVOUS-SYSTEM INVOLVEMENT

Opioids have been hypothesized to suppress parameters of immune functi on be acting within the central nervous system to increase the activit y of the hypothalamic-pituitary-adrenal axis and the sympathetic nervo us system. Production of catecholamines and adrenocorticoids have been demonstrated to be responsible for many of the observed immunomodulat ory effects which occur following opioid administration. In general, t he sympathetic nervous system has been shown to play a role in regulat ing lymphocyte proliferation and natural killer cell activity as well as several other parameters of immune function. Here, we will focus pr imarily on the role of the sympathetic nervous system in modulating op ioid induced immunosuppression. The role of the hypothalamic-pituitary -adrenal axis is reviewed elsewhere in this issue.