title: Inhibition of protein kinase C antagonizes in vitro tadpole tail fin regression induced by thyroxine.
abstract: Tail fin regression can be induced in anuran amphibians with L-thyroxine (T4). This regression can be antagonized with prolactin (PRL). Previous work had suggested that protein kinase C (PKC) was involved in PRL action. To address this issue further, the effect of a potent and selective inhibitor of protein kinase C on in vitro tail fin regression was investigated. T4-induced regression of tail fin pieces from Rana pipiens tadpoles could be antagonized by adding PRL or the PKC inhibitor H-7 to the medium. H-7 inhibited fin regression in a dose-dependent manner, with a half-maximal effective concentration of about 10(-5) M. The H-7 analogue, HA-1004 (which is not a selective inhibitor of PKC), was without effect. These results suggest a possible role for PKC in tail fin regression and may be useful in elucidating the antimetamorphic action of PRL.
authors.affiliation: Department of Biological Sciences, University of Denver, Colorado 80208.
authors.forename: D W
authors.initials: DW
authors.lastname: Petcoff
authors.forename: J E
authors.initials: JE
authors.lastname: Platt
mesh_terms: D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D000818:Animals; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D007546:Isoquinolines / Q000494:pharmacology; D008675:Metamorphosis, Biological / Q000187:drug effects / Q000502:physiology*; D010879:Piperazines / Q000494:pharmacology; D011388:Prolactin / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000502:physiology*; D011894:Rana pipiens / Q000502:physiology*; D013449:Sulfonamides; D013974:Thyroxine / Q000494:pharmacology
chemical_list: D007546:Isoquinolines; D010879:Piperazines; D013449:Sulfonamides; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D011388:Prolactin; C043204:N-(2-guanidinoethyl)-5-isoquinolinesulfonamide; D011493:Protein Kinase C; D013974:Thyroxine