title: Effects of corticotrophin-releasing factor and arginine-vasopressin on proopiomelanocortin (POMC) mRNA levels, release and storage of adrenocorticotrophin from mouse anterior pituitary cells.
abstract: 1. The present studies were undertaken to determine the effects of arginine vasopressin (AVP), corticotrophin-releasing factor (CRF) and AVP in combination with CRF on proopiomelanocortin (POMC) gene expression, and in the release and biosynthesis of POMC products (i.e. ACTH). 2. After a 3 hr treatment, AVP (10(-7) M), CRF (10(-7) M) and AVP (10(-7) M) in combination with CRF (10(-7) M) stimulated ACTH release by 291 +/- 19.2%, 377.4 +/- 25.6% and 462.1 +/- 38.4% (P < 0.01), respectively, with respect to basal secretion; while ACTH content diminished by 84.0 +/- 4.6%, 81.3 +/- 2.1% and 71.0 +/- 1.5% (P < 0.01), respectively, with respect to basal. Total POMC mRNA levels were not affected after a 3 hr treatment. 3. When cells were treated with a wide range of AVP concentrations (10(-11)-10(-7) M) to which we added different concentrations of CRF, modulation of AVP-induced ACTH release was most effective at CRF concentrations of < 10(-10) M. 4. Prolonged (3-6 hr) exposure to as low as 10(-10) M CRF or 10(-9) M AVP resulted in homologous desensitization of ACTH secretion. However, these pretreated cells were able to respond to a further challenge of CRF and AVP. This paper provides new information on the dose ranges over which desensitization and cross-sensitization between CRF and AVP secretory effects take place in mouse anterior pituitary cells.
authors.affiliation: Department of Molecular and Life Sciences, Dundee Institute of Technology, U.K.
authors.forename: M G
authors.initials: MG
authors.lastname: Castro
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000378:metabolism*; D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology*; D002478:Cells, Cultured; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D007424:Intracellular Fluid / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051379:Mice; D010903:Pituitary Gland, Anterior / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D011333:Pro-Opiomelanocortin / Q000096:biosynthesis / Q000187:drug effects* / Q000235:genetics*; D012333:RNA, Messenger / Q000187:drug effects*
chemical_list: D012333:RNA, Messenger; D001127:Arginine Vasopressin; D011333:Pro-Opiomelanocortin; D000324:Adrenocorticotropic Hormone; D003346:Corticotropin-Releasing Hormone