Effect of plasma lipoproteins in gonadotropin stimulation of 17β-estradiol production in the ovarian follicle of rainbow trout (Salmo gairdneri)

1986 ◽  
Vol 64 (3) ◽  
pp. 456-467 ◽  
Author(s):  
Patrick J. Babin
Keyword(s):  
Rainbow Trout ◽  
Ovarian Follicle ◽  
Plasma Lipoproteins ◽  
Salmo Gairdneri ◽  
Gonadotropin Stimulation ◽  
17Β Estradiol ◽  
Stimulation Of

Zinc Influx Across the Isolated, Perfused Head Preparation of the Rainbow Trout (Salmo gairdneri) in Hard and Soft Water

1988 ◽  
Vol 45 (12) ◽  
pp. 2206-2215 ◽  
Author(s):  
Douglas J. Spry ◽  
Chris M. Wood
Keyword(s):  
Steady State ◽  
Rainbow Trout ◽  
Hard Water ◽  
Soft Water ◽  
Chloride Cells ◽  
Salmo Gairdneri ◽  
First Order ◽  
Scanning Electron Micrography ◽  
Primary Substrate ◽  
Stimulation Of

At a waterborne [Zn] of 1.9 mg∙L−1 in hard water (~1 mmol Ca∙L−1), Zn influx across an isolated, saline-perfused head preparation of rainbow trout (Salmo gairdneri) was about 1.5 nmol∙kg−1∙h−1 through the lamellar pathway and about 1 nmol∙kg−1∙h−1 through the filamental route. Flux rates came rapidly to steady state in both pathways. Trout preexposed to artificial soft water (~0.05 mmol Ca∙L−1) for 5 d showed differential stimulation of flux rates to about 42 and 5 nmol Zn∙kg−1∙h−1 through the lamellar and filamental pathways, respectively. Under these conditions, steady-state fluxes across the lamellae did not occur until 15–20 min after the start of perfusion. Preparations from hardwater-acclimated trout tested in soft water gave typical hardwater fluxes showing that these changes in influx were not simply due to acute exposure of the gill surface to low waterborne [Ca]. Influxes in softwater trout, studied over [Zn] from 0.4 to 7.5 mg Zn∙L−1, revealed a saturable, first-order uptake with apparent Jmax and Km of 150 nequiv∙kg−1∙h−1 and 1.5 mg Zn∙L−1 (23 μmol∙L−1), respectively. Because the apparent Km is in the toxic range, Zn is clearly not the primary substrate. Scanning electron micrography revealed hypertrophy and increased apical exposure of chloride cells; this stimulation, coupled with the increase in Zn influx, suggests that chloride cells may be the site of entry of Zn across the gill.

Effect of Aroclor 1254 and Mirex on Estradiol-lnduced Vitellogenin Production in Juvenile Rainbow Trout (Salmo gairdneri)

1986 ◽  
Vol 43 (1) ◽  
pp. 169-173 ◽  
Author(s):  
Thomas T. Chen ◽  
P. C. Reid ◽  
R. Van Beneden ◽  
R. A. Sonstegard
Keyword(s):  
Rainbow Trout ◽  
Serum Levels ◽  
Salmo Gairdneri ◽  
Sensitive Assay ◽  
Aroclor 1254 ◽  
Juvenile Rainbow Trout ◽  
17Β Estradiol

A rapid sensitive assay for vitellogenin using rocket immunoelectrophoresis was developed in juvenile rainbow trout (Salmo gairdneri) induced with 17β-estradiol. The assay detected vitellogenin serum levels as low as 0.05 mg/mL. Significant reduction of vitellogenin levels were detected in rainbow trout fed for 6 mo on diets contaminated with Aroclor 1254, Mirex, or a mixture of Aroclor 1254 and Mirex.

Measurement of vitellogenin from rainbow trout by rocket immunoelectrophoresis: application to the kinetic analysis of estrogen stimulation in the male

1985 ◽  
Vol 63 (9) ◽  
pp. 982-987 ◽  
Author(s):  
Jean Louis Maitre ◽  
Catherine Le Guellec ◽  
Stephane Derrien ◽  
Martin Tenniswood ◽  
Yves Valotaire
Keyword(s):  
Rainbow Trout ◽  
Salmo Gairdneri ◽  
Immature Female ◽  
External Appearance ◽  
Seasonal Regulation ◽  
Low Levels ◽  
Estrogen Stimulation ◽  
Different Levels ◽  
Estradiol Levels ◽  
Stimulation Of

The study of the seasonal regulation of vitellogenesis in rainbow trout (Salmo gairdneri) is hampered by two features of the system which are not seen in species such as Xenopus. First, it is impossible to sex immature trout by external appearance and, secondly, the quantitation of the very low levels of vitellogenin in previtellogenic serum is technically difficult and tedious. We describe the preparation of a specific, sensitive anti-vitellogenin antibody and the use of this antibody in a rocket immunoelectrophoresis system to measure serum vitellogenin. The sensitivity of the assay is such that, using only 2 μL of serum, it is possible to detect vitellogenin at levels of 10 μg/mL, making this assay extremely useful for selecting immature female trout for further studies on the basis of the presence of vitellogenin. Using this system we have also measured the response of individual male trout to stimulation with different levels of estradiol, and we have shown that it is possible to measure the stimulation of vitellogenin by estradiol levels equivalent to those seen during the previtellogenic phase of the reproductive cycle in females. This simple assay system thus alleviates two of the major hurdles in studying vitellogenesis in trout.

Effects of Perfusate HCO3− and Pco2 on Chloride Uptake in Perfused Gills of Rainbow Trout (Salmo gairdneri)

1984 ◽  
Vol 41 (12) ◽  
pp. 1768-1773 ◽  
Author(s):  
S. F. Perry ◽  
P. Payan ◽  
J. P. Girard
Keyword(s):  
Rainbow Trout ◽  
Carbonic Anhydrase ◽  
Chloride Transport ◽  
Salmo Gairdneri ◽  
Gill Epithelium ◽  
Major Pathway ◽  
Chloride Uptake ◽  
Transport Inhibitors ◽  
Initial Results ◽  
Stimulation Of

Experiments were conducted using a saline-perfused trout (Salmo gairdneri) head preparation in an attempt to determine the origin of HCO3− involved in gill apical Cl−/HCO3− exchange, the possibilities being plasma CO2 or HCO3−. Initial results showed that branchial Cl− influx was stimulated both by increased perfusate [HCO3−] and Pco2. Subsequent experiments employing the chloride transport inhibitors, SITS and thiocyanate, indicated that stimulation of Cl− influx by HCO3− probably was due to gill hemodynamic alterations and not to increased entry of HCO3− into the gill epithelium. We conclude that CO2 entry into the gill epithelium from plasma and its subsequent hydration to HCO3− and H+, by carbonic anhydrase, is a major pathway by which HCQ3− for Cl−/HCO3− exchange is generated.

Influence of thiol substances on in vitro and in vivoL-thyroxine deiodination in rainbow trout, Salmo gairdneri

1984 ◽  
Vol 62 (8) ◽  
pp. 1495-1501 ◽  
Author(s):  
J. G. Eales ◽  
Shirley Shostak ◽  
Catherine G. Flood
Keyword(s):  
Rainbow Trout ◽  
Reduced Glutathione ◽  
Salmo Gairdneri ◽  
Physiological Conditions ◽  
Low Concentrations ◽  
Dtt Dithiothreitol ◽  
High Concentrations ◽  
Stimulation Of

The effects of the thiols DTT (dithiothreitol) and GSH (reduced glutathione) on hepatic in vitro and in vivo T4 (L-thyroxine) deiodination by rainbow trout held at 11 °C were studied. Hepatic deiodination increased progressively over the DTT range of 0.02–20 mM. GSH was less potent than DTT at low concentrations and strongly inhibited deiodination at high concentrations (> 1 mM). Hepatic deiodination was not increased by 1 mM NADPH or anaerobic conditions and was enhanced and not inhibited by the GSH inhibitor, diamide (2.5 mM), indicating that the low T4 deiodination in the absence of DTT is not due to endogenous GSH deficiency. Intraperitoneally injected GSH consistently increased plasma levels of 125I and [125I]-3,5,3′-triiodo-L-thyronine (T3) in fed or starved [125I]T4-injected trout, suggesting a GSH stimulation of extrahepatic T4 deiodination. However, injected GSH did not elevate plasma T3 concentrations. This was probably due to a demonstrated GSH stimulation of plasma T4 and T3 clearance. Force-fed GSH did not increase [125I]T4 deiodination. It is concluded that exogenous thiols can enhance T4 deiodination both in vitro and in vivo. However, availability of neither endogenous nor dietary GSH appears to regulate T4 deiodination under physiological conditions, including altered nutritional state.

Hepatic Biotransformation of Environmental Xenobiotics in Six Strains of Rainbow Trout (Salmo gairdneri)

1976 ◽  
Vol 33 (4) ◽  
pp. 666-675 ◽  
Author(s):  
Mark G. Pedersen ◽  
William K. Hershberger ◽  
Prince K. Zachariah ◽  
Mont R. Juchau
Keyword(s):  
Rainbow Trout ◽  
Salmo Gairdneri ◽  
Aminobenzoic Acid ◽  
Aryl Hydrocarbon Hydroxylase ◽  
Nitrobenzoic Acid ◽  
Aryl Hydrocarbon ◽  
Influence Gene Expression ◽  
Stimulation Of ◽  
Hepatic Biotransformation

Six strains of rainbow trout (Salmo gairdneri), each geographically and genetically distinct, were compared in relation to their capacity for hepatic hydroxylation of aniline and benzo[a]pyrene, and reduction of p-nitrobenzoic acid to p-aminobenzoic acid, in vitro. The effects of 3-methylcholanthrene on stimulation of nitro reductase and aryl hydrocarbon hydroxylase were examined. For the three systems studied, a significant pattern was observed with respect to each strain’s capacity for metabolism. Induction experiments suggested that environment may influence gene expression. Enzyme kinetics and spectral properties were also examined, and mechanisms causing variability within and among strains were discussed.

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