Effects of prolactin and growth hormone on plasma levels of lysozyme and ceruloplasmin in rainbow trout.
In vivo and in vitro effects of prolactin (PRL) and growth hormone (GH) on plasma levels of lysozyme and ceruloplasmin were examined in the rainbow trout (Oncorhynchus mykiss). Hypophysectomy had no effect on the plasma lysozyme level. Implantation of PRL- or GH-containing cholesterol pellets increased the lysozyme level in a dose-related manner. After hypophysectomy and sham operation, plasma ceruloplasmin was elevated above the level in intact fish, suggesting inflammation caused by the surgery. PRL or GH treatment significantly attenuated the increased level of ceruloplasmin in the operated fish. Expression of lysozyme mRNA was detected in the leucocytes isolated from the peripheral blood by RT-PCR. In vitro administration of PRL or GH showed no effect on the proliferation of isolated leucocytes or on the total protein content; however, lysozyme activity in the medium increased in a dose-related manner. These results suggest that PRL and GH directly stimulate lysozyme production without affecting the proliferation of leucocytes, and the attenuated ceruloplasmin level increased in response to inflammation.
Yada
Takashi
T
Freshwater Fisheries Research Division, National Research Institute of Fisheries Science, Nikko, Tochigi 321-1661, Japan. yadat@fra.affrc.go.jp
Muto
Kohji
K
Azuma
Teruo
T
Ikuta
Kazumasa
K
D000818:Animals; D002478:Cells, Cultured; D002570:Ceruloplasmin / Q000032:analysis / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004343:Drug Implants; D013006:Growth Hormone / Q000008:administration & dosage / Q000097:blood / Q000235:genetics / Q000494:pharmacology*; D007016:Hypophysectomy; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000276:immunology; D009113:Muramidase / Q000096:biosynthesis / Q000097:blood / Q000187:drug effects*; D017686:Oncorhynchus mykiss / Q000276:immunology*; D011388:Prolactin / Q000008:administration & dosage / Q000097:blood / Q000235:genetics / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors
D004343:Drug Implants; D012333:RNA, Messenger; D011388:Prolactin; D013006:Growth Hormone; D002570:Ceruloplasmin; D009113:Muramidase