The effect of thyroid hormone and glucocorticoids on carp growth hormone-releasing factor (GRF)-induced growth hormone (GH) release in rainbow trout (Oncorhynchus mykiss).
1. The effect of thyroid hormone and glucocorticoids on carp growth hormone-releasing factor (GRF)-induced growth hormone (GH) secretion was studied on rainbow trout using a dispersed pituitary cell culture system. 2. A combined administration of lower doses (0.01 microM) of 3,5,3'-triiodo-L-thyronine (T3) and dexamethasone (Dex) significantly increased spontaneous as well as carp GRF-induced GH release. 3. Lower doses of Dex alone had no effect, and T3 had a marginal effect on GH release. Higher doses of either Dex or T3 potentially reduced GH release. 4. This study indicates an important role of thyroid hormone and/or glucocorticoids in the hypothalamic regulation of GH secretion in fish.
Department of Biological Sciences, Simon Fraser University, Burnaby, B.C., Canada.
D
D
Luo
B A
BA
McKeown
D000818:Animals; D002347:Carps; D002478:Cells, Cultured; D003907:Dexamethasone / Q000494:pharmacology*; D013006:Growth Hormone / Q000378:metabolism; D013007:Growth Hormone-Releasing Hormone / Q000378:metabolism*; D010902:Pituitary Gland / Q000166:cytology / Q000378:metabolism*; D014284:Triiodothyronine / Q000502:physiology*; D014337:Trout / Q000502:physiology*
D014284:Triiodothyronine; D003907:Dexamethasone; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone