Bruce Nock Back to Faculty Listing Page . Most of our current research is derived from our recent discovery that chronic exposure to morphine upregulates corticosteroid-binding globulin in blood and, thereby, reduces the amount of physiologically active glucocorticoid available to intracellular receptors.
Glucocorticoids exert both permissive and suppressive actions to protect the body against stress.
Permissive actions are exerted by basal glucocorticoid levels which 'prime' defense mechanisms enabling them to be fully expressed in response to stress. Suppressive actions are exerted at stress levels and function to protect the body against damage from its own defense reactions which can be harmful if they continue unconstrained. Morphine appears to suppress both mechanisms. This is likely to adversely affect both mental and physical health over the long run and may contribute to the maintenance of drug use. Chronic exposure to morphine increases corticosteroid-binding globulin.