PSEUDOAROMATASE IN CIRCULATING LYMPHOCYTES

A variety a data suggesting a relationship between estrogens and the i mmune system prompted a study of aromatase activity in blood lymphocyt es. A tritiated water aromatase assay detected activity of 1.9 to 25.1 pmol/g protein/h in 14 samples of human lymphocytes. To confirm these results, additional tritiated water and product isolation assays were performed on a large pool of lymphocytes obtained from 4 U of blood. An assay using [1beta-H-3]androstenedione generated high apparent arom atase activity, 943 pmol/g protein/h, but this activity could not be b locked by the aromatase inhibitor, CGS 16949A. More direct methods of evaluation yielded the following results: (1) PCR demonstrated no arom atase mRNA production in lymphocytes; (2) direct product isolation usi ng [1,2,6,7-H-3]androstenedione yielded insignificant production of es trone and estradiol; (3) immunostaining of fixed lymphocyte smears wit h a polyclonal antibody to aromatase yielded equivocal results. These data suggest the presence of pseudoaromatase in blood lymphocytes. Sin ce circulating lymphocyte pseudoaromatase levels can be correlated wit h various factors in patients, such as age, menopausal status, and glu cose ingestion, further studies of this activity are warranted.