scholarly journals Partial Purification and Characterization of Rhodanese from Rainbow Trout (Oncorhynchus mykiss) Liver

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Hossein Tayefi-Nasrabadi ◽  
Reza Rahmani
Keyword(s):  
Rainbow Trout ◽  
Relative Activity ◽  
Tissue Homogenate ◽  
Partial Purification ◽  
Toxic Substances ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Liver Tissue Homogenate

Cyanide is one of the most toxic substances present in a wide variety of food materials that are consumed by animals. Rhodanese, a ubiquitous enzyme, can catalyse the detoxification of cyanide by sulphuration reaction. In this study, rhodanese was partially purified and characterized from the liver tissue homogenate of the rainbow trout. The enzyme was active in a broad range of pH, from 5 to 12. The optimal activity was found at a high pH (pH 10.5), and the temperature optimum was25∘C. The enzyme was heat labile, losing > 50% of relative activity after only 5 min of incubation at40∘C. TheKmvalues for KCN and Na2S2O3as substrates were 36.81 mM and 19.84 mM, respectively. Studies on the enzyme with a number of cations showed that the activity of the enzyme was not affected by Sn2+, but Hg2+, Ba2+, Pb2+, and Ca2+inhibited and Cu2+activated the enzyme with a concentration-dependent manner.

scholarly journals Biochemical and functional analysis of a conserved IGF-binding protein isolated from rainbow trout (Oncorhynchus mykiss) hepatoma cells

2001 ◽  
Vol 170 (3) ◽  
pp. 619-628 ◽  
Author(s):  
◽  
A Garmong ◽  
P Swanson ◽  
J Moore ◽  
M Lin ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Hepatoma Cells ◽  
Dependent Manner ◽  
High Sequence Identity ◽  
Concentration Dependent Manner ◽  
Igf Binding Proteins ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Igf I ◽  
Igf Binding

Rainbow trout (Oncorhynchus mykiss) serum contains several IGF-binding proteins (IGFBPs) that specifically bind to IGFs. The structures of these fish IGFBPs have not been determined and their physiological functions are poorly defined. In this study, we identified a 30 kDa IGFBP present in rainbow trout serum and secreted by cultured trout hepatoma cells. This IGFBP binds to IGFs but not to insulin. This IGFBP was purified to homogeneity using a three-step procedure involving Phenyl-Sepharose chromatography, IGF-I affinity chromatography and reverse-phase HPLC. Affinity cross-linking studies indicated that this IGFBP binds to IGF-I with a higher affinity than to IGF-II. N-terminal sequence analysis of the trout IGFBP suggests that it shares high sequence identity with that of human IGFBP-1 in the N-terminal region. When added to cultured fish and human cells, the trout IGFBP inhibited IGF-I-stimulated DNA synthesis and cell proliferation in a concentration-dependent manner. The inhibitory effect of the fish IGFBP was comparable to those of human IGFBP-1 and -4. These results indicate that the IGFBP molecule is structurally and functionally conserved in evolutionarily ancient vertebrate species such as bony fish.

Characterization of the muscarinic and serotoninergic receptors of the intestine of the rainbow trout (Salmo gairdneri)

1989 ◽  
Vol 67 (5) ◽  
pp. 477-482 ◽  
Author(s):  
John F. Burka ◽  
Rosalind M. J. Blair ◽  
Jane E. Hogan
Keyword(s):  
Smooth Muscle ◽  
Rainbow Trout ◽  
Salmo Gairdneri ◽  
Muscarinic Agonist ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Receptor Blockers ◽  
Ganglionic Blockers ◽  
Serotoninergic Receptors

The ability of carbachol and 5-hydroxytryptamine (5-HT) to contract isolated segments of rainbow trout intestine in a concentration-dependent manner indicates the presence of muscarinic and serotoninergic receptors in this tissue. The activity of these agonists appears to be directly on the smooth muscle, since ganglionic blockers and inhibitors of neurotransmission did not inhibit contractions. The carbachol-induced contractions were selectively inhibited by atropine and (±)-3-quinuclidinyl xanthene-9-carboxylate hemioxalate hydrate, an M-2 muscarinic receptor antagonist. However, the inhibition was not competitive. McN-A-343, an M-1 muscarinic agonist had no effect on intrinsic tone. The 5-HT-induced contractions were selectively inhibited by methysergide and the 5-HT2 receptor blockers, ketanserin and 1-(1-naphthyl)piperazine. Again, the inhibition by these agents was not competitive. 5-HT1 and 5-HT3 receptor antagonists did not inhibit contractions. The results thus suggest that the smooth muscle of the rainbow trout intestine contains M-2 muscarinic and 5-HT2 receptors.Key words: smooth muscle, gastrointestinal tract, trout, muscarinic receptors, serotonin.

Uptake of taurocholic acid and cholic acid in isolated hepatocytes from rainbow trout

1994 ◽  
Vol 267 (3) ◽  
pp. G380-G386 ◽  
Author(s):  
C. M. Rabergh ◽  
K. Ziegler ◽  
B. Isomaa ◽  
M. M. Lipsky ◽  
J. E. Eriksson
Keyword(s):  
Rainbow Trout ◽  
Bile Acids ◽  
Low Temperatures ◽  
High Efficiency ◽  
Isolated Hepatocytes ◽  
Metabolic Inhibitors ◽  
Dependent Manner ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Transport Component ◽  
Efficient Uptake

The uptake of the bile acids cholate (CHA) and taurocholate (TCHA) was studied in isolated hepatocytes from rainbow trout (Oncorhynchus mykiss). Both CHA and TCHA were taken up in a concentration- and temperature-dependent manner with optimum temperature at 15 degrees C and a strikingly efficient uptake even at low temperatures (0-5 degrees C). The total uptake was a combination of a saturable [Michaelis-Menten constant (Km) for CHA, 20 microM; Km for TCHA, 19 microM] and a nonsaturable component. The maximal uptake rate of the saturable component was 416 and 805 pmol.mg protein-1.min-1 for CHA and TCHA, respectively. The uptake of both bile acids was shown to be energy dependent, since it was inhibited by the metabolic inhibitors antimycin A, oligomycin and carbonyl cyanide m-chlorophenylhydrazone. The uptake was clearly Na+ independent, since isosmotic replacement of extracellular Na+ by Li+, choline, or K+ did not inhibit the uptake. Furthermore, it seemed to be independent of the presence of extracellular Cl-, since it was not inhibited by replacement of Cl- with sodium gluconate. On the whole, our results show that the hepatocellular uptake of bile acids in rainbow trout is mediated by a Na(+)-independent carrier system, with characteristics resembling the corresponding transport component in mammalian hepatocytes, but with high efficiency even at low temperatures.

Regulation of glucose production in rainbow trout: role of epinephrine in vivo and in isolated hepatocytes

2000 ◽  
Vol 278 (4) ◽  
pp. R956-R963 ◽  
Author(s):  
Jean-Michel Weber ◽  
Deena S. Shanghavi
Keyword(s):  
Rainbow Trout ◽  
Hepatic Glucose Production ◽  
Glucose Production ◽  
Isolated Hepatocytes ◽  
Relative Increase ◽  
Dependent Manner ◽  
Rainbow Trout Oncorhynchus Mykiss

The rate of hepatic glucose production (Ra glucose) of rainbow trout ( Oncorhynchus mykiss) was measured in vivo by continuous infusion of [6-3H]glucose and in vitro on isolated hepatocytes to examine the role of epinephrine (Epi) in its regulation. By elevating Epi concentration and/or blocking β-adrenoreceptors with propranolol (Prop), our goals were to investigate the mechanism for Epi-induced hyperglycemia to determine the possible role played by basal Epi concentration in maintaining resting Ra glucose and to assess indirect effects of Epi in the intact animal. In vivo infusion of Epi caused hyperglycemia (3.75 ± 0.16 to 8.75 ± 0.54 mM) and a twofold increase in Ra glucose (6.57 ± 0.79 to 13.30 ± 1.78 μmol ⋅ kg− 1 ⋅ min− 1, n = 7), whereas Prop infusion decreased Ra from 7.65 ± 0.92 to 4.10 ± 0.56 μmol ⋅ kg− 1 ⋅ min− 1( n = 10). Isolated hepatocytes increased glucose production when treated with Epi, and this response was abolished in the presence of Prop. We conclude that Epi-induced trout hyperglycemia is entirely caused by an increase in Ra glucose, because the decrease in the rate of glucose disappearance normally seen in mammals does not occur in trout. Basal circulating levels of Epi are involved in maintaining resting Ra glucose. Epi stimulates in vitro glucose production in a dose-dependent manner, and its effects are mainly mediated by β-adrenoreceptors. Isolated trout hepatocytes produce glucose at one-half the basal rate measured in vivo, even when diet, temperature, and body size are standardized, and basal circulating Epi is responsible for part of this discrepancy. The relative increase in Ra glucose after Epi stimulation is similar in vivo and in vitro, suggesting that indirect in vivo effects of Epi, such as changes in hepatic blood flow or in other circulating hormones, do not play an important role in the regulation of glucose production in trout.

Sign in / Sign up

Export Citation Format

Share Document