Secretion of corticotrophin releasing factor-like activity by a human bronchial carcinoid cell line

The production of corticotrophin releasing factor (CRF) activity by human tumour cells in monolayer culture was investigated. The secretion of CRF activity by a bronchial carcinoid cell line was demonstrated using a rat pituitary cell monolayer system. The long-term production (5 years) of CRF activity suggested the synthesis and secretion of active factors by the tumour cells. The CRF activity was concentrated from medium previously exposed to the tumour cells using batchwise extraction on columns packed with ODS. When these extracts were fractionated by analytical high pressure liquid chromatography, the CRF activity was resolved into two molecular forms.