Studies on ectopic ACTH-producing tumours. IV. CRF-like activity in tumour tissue
Yamamoto, H.; Hirata, Y.; Matsukura, S.; Imura, H.; Nakamura, M.; Tanaka, A.
Acta Endocrinologica 82(1): 183-192
1976
ISSN/ISBN: 0001-5598 PMID: 178136 Document Number: 101221
To elucidate whether ectopic ACTH-producing tumors elaborate corticotropin-releasing factors (CRF)-like materials, the CRF-like activity of tumor extracts was measured by the in vitro pituitary incubation method. Seven of 12 tumor extracts with suspected ACTH-producing tumors showed CRF-like activity. No correlation was found between ACTH and CRF-like activities in tumor extracts in which both activities were present. The dose-response curve of a tumor extract was almost parallel to that of crude CRF (NIAMDD [National Institute of Arthritis, Metabolism and Digestive Diseases]) and different from those of lysine-8-vasopressin and arginine-vasopressin, both of which showed CRF-like activity by this assay method. Trypsin digestion lowered the CRF-like activity of a tumor extract. Ectopic production CRF-like substance(s) probably occurs more frequently than was supposed previously, especially in ACTH-producing tumors.