Cortisol reduces cell proliferation in the telencephalon of rainbow trout (Oncorhynchus mykiss)

2011 ◽  
Vol 102 (5) ◽  
pp. 518-523 ◽  
Author(s):  
Christina Sørensen ◽  
Linda C. Bohlin ◽  
Øyvind Øverli ◽  
Göran E. Nilsson
1994 ◽  
Vol 72 (8) ◽  
pp. 1395-1402 ◽  
Author(s):  
Shawn D. Bindon ◽  
James C. Fenwick ◽  
Steve F. Perry

The effects of branchial chloride cell proliferation on ion transport capability and gill morphometry were evaluated in the rainbow trout, Oncorhynchus mykiss, to test the hypothesis that chloride cell (CC) proliferation benefits ionic regulation at the expense of efficient gas transfer. The extent of hormone-induced CC proliferation (using ovine growth hormone (oGH), cortisol, or a combination of both) on the gill filament epithelium was assessed by determining the fractional surface area of exposed cells using scanning electron microscopy. Cortisol and oGH were equally effective in increasing CC fractional surface area (~2×), owing to the enlargement of individual CCs. The combined cortisol/oGH treatment resulted in an even greater increase in CC fractional area (~6×), as both the size and number of CCs increased. Sham injections were without effect on CC surface area or number. Significant increases in Na+ (Jin Na+) and Cl− uptake (Jin Cl−) were observed after all hormone treatments and were correlated positively with the increases in the CC fractional surface area. These findings support the view that CC proliferation enhances branchial ion transport capability. Lamellar epithelial thickness (measured by transmission electron microscopy) was increased in hormone-treated fish, while lamellar surface area (measured using light microscopy) was unaffected. The area of the interlamellar water channels (calculated from light micrographs) was significantly reduced in hormone-treated fish. These results suggest that, in trout, a compromise is made between the efficiency of ion regulation and gas transfer in which the enlargement/proliferation of CCs may impede gas transfer.


2008 ◽  
Vol 198 (3) ◽  
pp. 459-469 ◽  
Author(s):  
L Bouraoui ◽  
J Gutiérrez ◽  
I Navarro

Here, we describe optimal conditions for the culture of rainbow trout (Oncorhynchus mykiss) pre-adipocytes obtained from adipose tissue and their differentiation into mature adipocytes, in order to study the endocrine control of adipogenesis. Pre-adipocytes were isolated by collagenase digestion and cultured on laminin or 1% gelatin substrate. The expression of proliferating cell nuclear antigen was used as a marker of cell proliferation on various days of culture. Insulin growth factor-I stimulated cell proliferation especially on days 5 and 7 of culture. Tumor necrosis factor α (TNFα) slightly enhanced cell proliferation only at a low dose. We verified the differentiation of cells grown in specific medium into mature adipocytes by oil red O (ORO) staining. Quantification of ORO showed an increase in triglycerides throughout culture. Immunofluorescence staining of cells at day 11 revealed the expression of CCAAT/enhancer-binding protein and peroxisome proliferator–activator receptor γ, suggesting that these transcriptional factors are involved in adipocyte differentiation in trout. We also examined the effect of TNFα on the differentiation of these adipocytes in primary culture. TNFα inhibited the differentiation of these cells, as indicated by a decrease in glycerol-3-phosphate dehydrogenase activity, an established marker of adipocyte differentiation. In conclusion, the culture system described here for trout pre-adipocytes is a powerful tool to study the endocrine regulation of adipogenesis in this species.


2012 ◽  
Vol 227 (2) ◽  
pp. 311-318 ◽  
Author(s):  
Christina Sørensen ◽  
Göran E. Nilsson ◽  
Cliff H. Summers ◽  
Øyvind Øverli

Sign in / Sign up

Export Citation Format

Share Document