Estrogen-Like Activity of Perfluoroalkyl Acids In Vivo and Interaction with Human and Rainbow Trout Estrogen Receptors In Vitro

We have isolated from a rainbow trout (Oncorhynchus mykiss) spleen cDNA library a clone coding for vimentin. The deduced amino acid sequence reveals a high degree of identity with vimentin from carp (81%), frog (71%), chick and human (73% each). Large stretches in the central alpha-helical rod are identical within all four classes of vertebrates, but in 17 residues spread over the entire rod, the two fish differ distinctly from the tetrapod species. In addition, in the more diverged non-helical head domain, a nonapeptide motif previously shown to be important for regular filament formation is conserved. Recombinant trout vimentin assembles into bona fide filaments in vitro, with a temperature optimum between 18 and 24 degrees C. Above 27 degrees C, however, filament assembly is abruptly abolished and short filaments with thickened ends as well as structures without typical intermediate filament appearance are formed. This distinguishes its assembly properties significantly from amphibian, avian and mammalian vimentin. Also in vivo, after cDNA transfection into vimentin-free mammalian epithelial cells, trout vimentin does not form typical intermediate filament arrays at 37 degrees C. At 28 degrees C, and even more pronounced at 22 degrees C, the vimentin-positive material in the transfected cells is reorganized in the perinuclear region with a partial fibrillar appearance, but typical intermediate filament arrays are not formed. Together with immunoblotting and immunolocalization data from trout tissues, where vimentin is predominantly found in glial and white blood cells, we conclude that vimentin is indeed important in its filamentous form in fish and other vertebrates, possibly fulfilling cellular functions not directly evident in gene targeting experiments carried out in mice.

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

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.2000.278.4.r956 ◽

2000 ◽

Vol 278 (4) ◽

pp. R956-R963 ◽

Cited By ~ 14

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.

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Mechanism of Action of Progestins in the Treatment of Hormone-dependent Breast Cancer.

Tumori Journal ◽

10.1177/030089167506100601 ◽

1975 ◽

Vol 61 (6) ◽

pp. 501-508 ◽

Cited By ~ 5

Author(s):

Francesco Di Carlo ◽

Giovanni Pacilio ◽

Giuseppe Conti

Keyword(s):

Breast Cancer ◽

Estrogen Receptors ◽

Mechanism Of Action ◽

Mode Of Action ◽

Binding Capacity ◽

Specific Receptors ◽

High Concentrations ◽

Good Agreement

The in vitro interference of some gestagens with the binding of 3H-17 β-oestradiol to cytosol specific receptors was investigated with a view to elucidating the mechanism of action of progestins in the treatment of human hormone-dependent breast cancer. A decrease (up to 85 %) of oestradiol binding capacity was observed with high concentrations of progesterone, clogestone and medrogestone. These findings are in good agreement with those previously obtained by the same progestins in our laboratory on rat uterine estrogen receptors in vitro or in vivo. These results provide support for the hypothesis that the mode of action of progestins in the therapy of mammary and perhaps uterine carcinomas is to some extent related to the inhibition of oestradiol binding to cytosol specific receptors.

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In vitro-in vivo extrapolation of hepatic and gastrointestinal biotransformation rates of hydrophobic chemicals in rainbow trout

Aquatic Toxicology ◽

10.1016/j.aquatox.2020.105629 ◽

2020 ◽

Vol 228 ◽

pp. 105629

Author(s):

Leslie J. Saunders ◽

Patrick N. Fitzsimmons ◽

John W. Nichols ◽

Frank A.P.C. Gobas

Keyword(s):

Rainbow Trout ◽

In Vivo Extrapolation

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In vivo virulence of viral haemorrhagic septicaemia virus (VHSV) in rainbow trout Oncorhynchus mykiss correlates inversely with in vitro Mx gene expression

Veterinary Microbiology ◽

10.1016/j.vetmic.2016.02.012 ◽

2016 ◽

Vol 187 ◽

pp. 31-40 ◽

Cited By ~ 13

Author(s):

Irene Cano ◽

Bertrand Collet ◽

Clarissa Pereira ◽

Richard Paley ◽

Ronny van Aerle ◽

...

Keyword(s):

Gene Expression ◽

Rainbow Trout ◽

Oncorhynchus Mykiss ◽

Haemorrhagic Septicaemia ◽

Rainbow Trout Oncorhynchus Mykiss ◽

Viral Haemorrhagic Septicaemia Virus

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Mechanisms of zinc uptake in gills of freshwater rainbow trout: interplay with calcium transport

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1996.270.5.r1141 ◽

1996 ◽

Vol 270 (5) ◽

pp. R1141-R1147 ◽

Cited By ~ 25

Author(s):

C. Hogstrand ◽

P. M. Verbost ◽

S. E. Bonga ◽

C. M. Wood

Keyword(s):

Rainbow Trout ◽

Control Level ◽

Inhibitory Effect ◽

Chloride Cells ◽

Water Addition ◽

Uptake Mechanism ◽

Basolateral Membranes ◽

Control Value

The uptake mechanism of Zn2+ through the gill epithelium of freshwater rainbow trout was investigated both in intact animals and in isolated basolateral membranes. Involvement of the apical Ca2+ uptake sites in Zn2+ uptake was examined in vivo by pharmacological manipulation of the apical Ca2+ permeability. The apical entries of Ca2+ and Zn2+, but not Na2+ and Cl-, were inhibited by addition of La to the water. Addition of 1.0 microM La reduced the influxes of Ca2+ and Zn2+ to 22 +/- 3 and 53 +/- 7% (mean +/- SE) of the control value, respectively. Injection of CaCl2 also reduced the branchial influxes of Ca2+ and Zn2+. This treatment decreased the influx of Ca2- to 45 +/- 4% of the control level and the Zn2+ influx to 68 +/- 5%. These results strongly imply that Zn2+ passes across the apical membrane of the chloride cells of the gills via the same pathway as Ca2+. The presence of an active basolateral transporter for Zn2+ was investigated in vitro on isolated basolateral membranes. There was no ATP-dependent or Na2+(-)gradient driven transport of Zn2+ at physiological Zn2+ activities. The same system was used to study potential effects of Zn2+ on the basolateral Ca2+(-)adenosinetri-phosphatase. Zn2+ was found to be a potent blocker of this transporter, causing a mixed inhibitory effect on the ATP driven Ca2+ transport at a free Zn2+ activity of 100 pM.

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Comparison of zebrafish in vitro and in vivo developmental toxicity assessments of perfluoroalkyl acids (PFAAs)

Journal of Toxicology and Environmental Health Part A ◽

10.1080/15287394.2020.1842272 ◽

2020 ◽

Vol 84 (3) ◽

pp. 125-136

Author(s):

Ola Wasel ◽

Kathryn M. Thompson ◽

Yu Gao ◽

Amy E. Godfrey ◽

Jiejun Gao ◽

...

Keyword(s):

Developmental Toxicity ◽

Perfluoroalkyl Acids

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Cadmium and calcium uptake in isolated mitochondria-rich cell populations from the gills of the freshwater rainbow trout

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00217.2005 ◽

2006 ◽

Vol 291 (1) ◽

pp. R170-R176 ◽

Cited By ~ 12

Author(s):

Fernando Galvez ◽

Denise Wong ◽

Chris M. Wood

Keyword(s):

Rainbow Trout ◽

Cellular Localization ◽

Calcium Uptake ◽

High Capacity ◽

Cell Types ◽

Isolation Technique ◽

Pavement Cells ◽

Gill Cells

A novel cell isolation technique was used to characterize cadmium and calcium uptake in distinct populations of gill cells from the adult rainbow trout ( Oncorhynchus mykiss). A specific population of mitochondria-rich (MR) cell, termed the PNA+ MR cell (PNA is peanut lectin agglutinin), was found to accumulate over threefold more 109Cd than did PNA− MR cells, pavement cells (PV cells), and mucous cells during a 1-h in vivo exposure at 2.4 μg/l 109Cd. In vitro 109Cd exposures, performed in standard PBS and Cl−-free PBS, at concentrations from 1 to 16 μg/l 109Cd, were also carried out to further characterize Cd2+ uptake kinetics. As observed during in vivo experiments, PNA+ MR cells accumulated significantly more 109Cd than did other cell types when exposures were performed by an in vitro procedure in PBS. Under such conditions, Cd2+ accumulation kinetics in all cell types could be described with Michaelis-Menten relationships, with Km values of ∼3.0 μg/l Cd (27 nM) for both MR cell subtypes and 8.6 μg/l Cd (77 nM) for PV cells. In similar experiments performed in Cl−-free conditions, a significant reduction in 109Cd accumulation in PNA+ MR cells was seen but not in PNA− MR or in PV cells. In vitro 45Ca fluxes were also performed to determine the cellular localization of Ca2+ transport in these functionally distinct populations of gill cells. 45Ca uptake was most pronounced in PNA+ MR cells, with levels over threefold higher than those found in either PNA− MR or in PV cells. Results from the present study suggest that the PNA+ MR cell type is a high-affinity and high-capacity site for apical entry of Cd2+ and Ca2+ in the gill epithelium of rainbow trout.

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