[In vitro effects of IL-2 on human hypophyseal adenoma]

The effects of two different concentrations of IL-2 on human pituitary adenomas (one secreting ACTH and one secreting GH) were evaluated in vitro. A specimen of the tumor was dissagregated and the cells were incubated for three days with RPMI 1640 medium. The medium was then decanted and the cells were incubated with 1 mlo of fresh medium for three hours and then with new fresh medium containing two different concentrations of IL-2, 100U/ml, for three hours too. The pituitary hormones, ACTH and GH, released into the medium were assayed by RIA. Dose of 100 U IL-2 induced a profound increase of ACTH release. The other dose decreased ACTH release. The release of GH was suppressed by IL-2 at the two concentrations tested. IL-2 may be an immunologic messenger exerting direct action at pituitary level. It appears probable that IL-2 plays an important role in determining the response of the pituitary to stress and infections.