Preparation of enriched populations of corticotrophs from goldfish rostral pars distalis.
A mammalian isolated adrenal cell system was validated as a bioassay for goldfish ACTH; the log dose-response curve for the goldfish hormone is parallel to that for synthetic mammalian ACTH1-24, and the two ACTHs induce the same maximum rate of corticosterone production. Using this assay, it was observed that (1) there is a marked and consistent biphasic change in pituitary ACTH content as related to the length of time the fish are held in laboratory aquaria, and (2) the absolute and relative (to tissue wt) ACTH content of the rostral pars distalis is considerably greater than that of the proximal portion of the gland. Using a trypsin technique, isolated pituitary cells were prepared from both (rostral and proximal) portions of the gland; bioassay data indicate that cell suspensions prepared from the rostral pars distalis are enriched with respect to corticotrophs. The implications of these findings with regard to formulating an advantageous in vitro system for studying ACTH secretion are discussed.
D000302:Adrenal Cortex / Q000187:drug effects / Q000378:metabolism; D000324:Adrenocorticotropic Hormone / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D001681:Biological Assay; D003345:Corticosterone / Q000096:biosynthesis; D003366:Cosyntropin / Q000494:pharmacology; D003530:Cyprinidae / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D006054:Goldfish / Q000378:metabolism*; D007700:Kinetics; D010903:Pituitary Gland, Anterior / Q000166:cytology / Q000378:metabolism*; D051381:Rats
D003366:Cosyntropin; D000324:Adrenocorticotropic Hormone; D003345:Corticosterone