scholarly journals STIMULATION OF REPRODUCTIVE GROWTH IN RAINBOW TROUT (ONCORHYNCHUS MYKISS) FOLLOWING EXPOSURE TO TREATED SEWAGE EFFLUENT

2006 ◽  
Vol 25 (10) ◽  
pp. 2753 ◽  
Author(s):  
Birgit Höger ◽  
Sean Taylor ◽  
Bettina Hitzfeld ◽  
Daniel R. Dietrich ◽  
Michael R. van den Heuvel
2004 ◽  
Vol 70 (4) ◽  
pp. 345-355 ◽  
Author(s):  
Birgit Hoeger ◽  
Michael R. van den Heuvel ◽  
Bettina C. Hitzfeld ◽  
Daniel R. Dietrich

2010 ◽  
Vol 299 (1) ◽  
pp. R33-R41 ◽  
Author(s):  
L. Bouraoui ◽  
E. Capilla ◽  
J. Gutiérrez ◽  
I. Navarro

Primary cultures of rainbow trout ( Oncorhynchus mykiss ) adipocytes were used to examine the main signaling pathways of insulin and insulin-like growth factor I (IGF-I) during adipogenesis. We first determined the presence of IGF-I receptors (IGF-IR) and insulin receptors (IR) in trout preadipocytes ( day 5) and adipocytes ( day 14). IGF-IRs were more abundant and appeared to be in higher levels in differentiated cells than in preadipocytes, whereas IRs were detected in lower but constant levels throughout the culture. The cells were immunoreactive against ERK1/2 MAPK, and AKT/PI3K, components of the two main signal transduction pathways for insulin and IGF-I receptors. Stimulation of MAPK phosphorylation by IGF-I was higher in preadipocytes than in adipocytes, while no effects were observed in MAPK phosphorylation after incubation of cells with insulin. AKT phosphorylation increased in the presence of both insulin and IGF-I, with higher levels of stimulation in adipocytes than in preadipocytes. Activation of both pathways was blocked by the use of specific inhibitors of MAPK (PD98059) and AKT (wortmannin). We describe here, for the first time, the effects of IGF-I and insulin on 2-deoxyglucose uptake in primary culture of trout adipocytes. IGF-I was more potent in stimulating glucose uptake than insulin, and PD98059 and wortmannin inhibited the stimulation of glucose uptake by this growth factor, suggesting that IGF-I plays an important metabolic role in trout adipocytes. Our results suggest that differential activation of the MAPK and AKT pathways are involved in the IGF-I- and insulin-induced effects of trout adipocytes during the various stages of adipogenesis.


1994 ◽  
Vol 51 (8) ◽  
pp. 1791-1798 ◽  
Author(s):  
C. J. A. Mitton ◽  
D. G. McDonald

Electrofishing, a technique widely used for fish collection, is a procedure that is often followed by handling and air exposure before fish are released. In this study the pathological and physiological consequences of capture with pulsed DC (pDC) electroshock with and without the additional disturbance of air exposure were examined on rainbow trout (Oncorhynchus mykiss). Electroshocked fish showed no evidence of direct mortality, and skeletal damage was only induced under the most severe conditions (~600-g fish, 600 V, 20 or 40 s). Physiological disturbances induced by pDC, in the absence of physical damage, consisted of lactacidosis and stimulation of the interrenal stress response. The acidosis was likely induced by tetany during immobilization and apnea during immobilization and early recovery. In fact, the physiological disturbances induced by pDC were similar in magnitude and duration to 2–3 min of exhaustive exercise and generally more severe than responses previously reported for nonpulsed (i.e., continous) DC gear. In addition, following pDC, fish appeared to experience a mild narcosis, as was evident by a reduced response to the additional stress of air exposure.


1994 ◽  
Vol 72 (5) ◽  
pp. 950-953 ◽  
Author(s):  
Dawn H. Sephton ◽  
William R. Driedzic

Whole blood from rainbow trout (Oncorhynchus mykiss) was incubated in vitro with pharmacological levels of isoproterenol. The adrenergic stimulation of glycolysis in erythrocytes (RBCs) was assessed by monitoring the rate of 14C incorporation from [6-14C]-glucose into the acid-soluble RBC fraction. During a 3-h in vitro incubation, incorporation of label into the acid-soluble RBC fraction of isoproterenol-treated whole blood (0.25 ± 0.04 μmol glucose∙mL−1 RBC∙h−1) was higher than into untreated blood (0.08 ± 0.01 μmol glucose∙mL−1 RBC∙h−1). The percentage of cell membrane binding for phosphofructokinase, aldolase, and glyceraldehyde-3-phosphate dehydrogenase ranged from 17 to 35% and was not altered by adrenergic stimulation. Adrenergic stimulation activates glycolysis in rainbow trout RBCs but not through the modulation of enzyme binding.


1992 ◽  
Vol 263 (2) ◽  
pp. R447-R451
Author(s):  
W. H. Powell ◽  
H. A. Miller

A substance that cross-reacts with antiserum to human atrial natriuretic peptide (ANP) is found in fish hearts. This ANP-like material increases sodium output from the gill and kidney while inhibiting sodium uptake in the gut. Mammalian ANP secretion is stimulated by glucocorticoids, and cortisol injection increases sodium output in salt-loaded fish. Therefore, we wanted to determine if the release of ANP in fish is sensitive to dexamethasone. Ventricle cardiocytes from the rainbow trout Oncorhynchus mykiss were treated with various doses of dexamethasone for 18 or 72 h. Single ventricle cells were then assayed for ANP release using a reverse hemolytic plaque assay and antiserum to human alpha-ANP. Incubation with 100 microM dexamethasone almost doubled the population of ventricle cells committed to ANP release (basal, 15.0 +/- 0.3% vs. Dexamethasone, 28.3 +/- 1.4%; values are percent plaque formation +/- SE). Stimulation of ANP secretion was dependent on dose and time of exposure to dexamethasone. These results suggest that ANP secretion in fish is regulated by glucocorticoids.


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