期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:1981
卷号:78
期号:8
页码:5197-5201
DOI:10.1073/pnas.78.8.5197
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:The presence of a corticotropin-releasing factor (CRF) behaving as a peptide with a molecular weight of about 5000 was established after purification of porcine hypothalamic extracts by gel filtration on Sephadex G-25 and then on Sephadex G-50. Purified CRF stimulated the release of corticotropin (ACTH) in three in vitro systems: isolated rat pituitary quarters, monolayer cultures of dispersed pituitary cells, and superfused pituitary cells on a column. A linear logarithmic dose-response relationship existed between 50 and 200 micrograms of CRF preparations per ml and the total amount of ACTH released by the superfused pituitary cells. The pituitary ACTH response to CRF in the pituitary quarters system was also approximately linearly related to the logarithm of the dose of CRF. CRF also stimulated in vivo release of ACTH in rats pretreated with chlorpromazine, morphine, and Nembutal. CRF activity was labile to digestion with trypsin and chymotrypsin and was partially destroyed by pepsin. The evidence indicates that CRF of porcine origin is a polypeptide of a higher molecular weight than previously assumed.