CRF immunoreactive peptides in the human hypophysis: a cautionary note

By monitoring with a non competitive enzyme linked immunosorbent assay (ELISA), corticotropin releasing factor (CRF)-like immunoreactive material was isolated from the human hypophysis. After acid extraction of peptides from frozen human hypophyses, the purification was achieved by affinity chromatography using purified anti-ovine-CRF IgG bound to a solid phase and then by two HPLC steps using an alkylsilane-bonded large pore size silica. Two CRF-like peptides were purified: discrete immunoreactive peaks coinciding with an optical density peak at 215 nm. Although these peptides were recognized by ELISA, they were not recognized in an RIA using the same anti-ovine-CRF serum and ovine CRF-41 as tracer. Neither of these CRF-immunoreactive peptides had any effect on either the spontaneous or stimulated ACTH release in the perfused isolated anterior pituitary cell bioassay.