Influence of plasma lipid changes in response to 17 beta-oestradiol stimulation on plasma growth hormone, somatostatin, and thyroid hormone levels in immature rainbow trout
2001
Mercure, Francois | Holloway, Alison C | Tocher, Douglas R | Sheridan, Mark A | Van der Kraak, Glen | Leatherland, John F | University of Guelph | University of Guelph | Institute of Aquaculture | North Dakota State University | University of Guelph | University of Guelph | 0000-0002-8603-9410
Plasma total lipids were significantly higher in 17β-oestradiol(E2)-treated immature rainbow trout Oncorhynchus mykiss at week 4 after implantation, due to increases in polar and neutral lipids. The lipid classes responding were phosphatidylcholine, phosphatidylinositol, phosphatidylethanolamine, sterols and sterol esters, in a proportion that approximately reflected the increase in plasma vitellogenin (VtG) levels as measured by a non-competitive enzyme-linked immunosorbent assay (ELISA). Plasma non-esterified fatty acids and triacylglycerol were not affected by E2 treatment. Plasma growth hormone GH levels were increased, and plasma somatostatin-14 (SRIF) levels decreased in E2-treated fish, responses which could be secondary to elevated plasma lipid (VtG) content, although a direct E2 action on somatotroph function is possible. Plasma T4 concentrations were not affected by E2 treatment, but plasma T3 concentrations were significantly lower than in controls 1 week after implantation when plasma E2 concentrations were the highest; this is in support of the hypothesis that E2 has a suppressive action on T3 production.
显示更多 [+] 显示较少 [-]