title: In vitro trophic effects of synthetic ACTH1-24.
abstract: In vitro trophic effects of adrenocorticotrophin1-24 (ACTH1-24, Synacthen) on adrenal cells were studied, using an in vitro assay system of guinea-pig adrenal segments kept in organ culture. Two separate methods for detecting growth activity were used, namely the measurement of thymidine kinase and a nucleic acid cytophotometric method. Synthetic ACTH was able to induce growth in the adrenal explants at very low concentrations (10-25 fg ml-1). Biphasic dose-response curves were obtained, comparable to those described for other cytochemical bioassays. The principles of this assay system may allow the development of a new bioassay for the measurement of plasma concentrations of ACTH or antibodies mimicking the growth effect of this trophic hormone.
mesh_terms: D000302:Adrenal Cortex / Q000187:drug effects*; D000324:Adrenocorticotropic Hormone / Q000031:analogs & derivatives*; D000818:Animals; D002453:Cell Cycle / Q000187:drug effects; D002467:Cell Nucleus / Q000648:ultrastructure; D003366:Cosyntropin / Q000494:pharmacology*; D004247:DNA / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D006168:Guinea Pigs; D007399:Interphase / Q000187:drug effects; D009924:Organ Culture Techniques; D013937:Thymidine Kinase / Q000378:metabolism
chemical_list: D003366:Cosyntropin; D000324:Adrenocorticotropic Hormone; D004247:DNA; D013937:Thymidine Kinase