RELATIONSHIP BETWEEN PSYCHOLOGICAL STRESS AND LYMPHOCYTIC 5'-ECTONUCLEOTIDASE

The relationship between psychological stress and lymphocytic 5'-ecton ucleotidase, an enzyme marker for lymphocyte differentiation, was stud ied. Lymphocytic 5'-ectonucleotidase was decreased significantly by ab out twofold in persons experiencing psychological stress, with a corre sponding change in Total Mood Disturbance scores of the Profile of Moo d States. Enzyme values were reversible in that they returned to norma l once the stress had been reduced. Administration of high doses of as corbate to severely depressed patients also normalized 5'-ectonucleoti dase activities, and implied that low enzyme values in stressed person s may be mediated by oxygen radical damage. This finding was consisten t with previous reports of heightened inflammatory responses occurring in depressed patients. The primary cause of lowered 5'-ectonucleotida se during stress may be the breakdown in the homeostatic mechanisms of the hypothalamic-pituitary-adrenal axis and immune system resulting i n lymphoid tissue resistance to corticosteroids. It is suggested that this lowering of lymphocyte 5'-ectonucleotidase may contribute to stre ss-mediated immune suppression by inhibiting lymphocyte maturation.