Corticotropin-releasing factor-like activity in ACTH producing tumors.
Corticotropin-releasing factor (CRF)-like activity in two different kinds of ACTH-producing tumors (human ectopic ACTH-producing colonic cancer and rat MtT/F4 tumor) was determined by an in vitro method using isolated normal rat pituitary cells. The ACTH content of the post mortem colonic cancer was 5.5 ng/g w.wt. The ACTH content of the medium of MtT/F4 tumor cells was 153+/-32 pg/10(5) cells. The ACTH content of MtT/F4 tumor cell suspensions was elevated with increasing doses of hypothalamic median eminence extract (HME). The response of MtT/F4 tumor cells to HME was suppressed by 1 mug/ml of dexamethasone. Extracts of colonic cancer, MtT/F4 tumor and HME produced elevation of the ACTH content of the medium of isolated rat pituitary cells. The CRF-like activities of two kinds of tumor extracts in multiple dilutions ran parallel to that of HME. The CRF-like activities were 0.037 HME equiv/mg w.wt in MtT/F4 tumor and 0.052 HME equiv/mg w.wt. in colonic cancer. These results demonstrated that CRF-like activity existed in these two kinds of ACTH-producing tumors.
D000324:Adrenocorticotropic Hormone / Q000096:biosynthesis*; D000818:Animals; D002460:Cell Line; D002540:Cerebral Cortex / Q000378:metabolism; D003110:Colonic Neoplasms / Q000378:metabolism*; D003346:Corticotropin-Releasing Hormone / Q000378:metabolism*; D003907:Dexamethasone; D005260:Female; D013006:Growth Hormone / Q000096:biosynthesis; D006729:Hormones, Ectopic / Q000096:biosynthesis*; D006801:Humans; D008473:Median Eminence / Q000378:metabolism; D008797:Metyrapone; D008875:Middle Aged; D009374:Neoplasms, Experimental / Q000378:metabolism; D011388:Prolactin / Q000096:biosynthesis; D051381:Rats
D006729:Hormones, Ectopic; D003907:Dexamethasone; D000324:Adrenocorticotropic Hormone; D011388:Prolactin; D013006:Growth Hormone; D003346:Corticotropin-Releasing Hormone; D008797:Metyrapone