Survival of larval summer flounder Paralichthys dentatus on formulated diets and failure of thyroid hormone treatment to improve performance

2000 ◽  
Vol 6 (3) ◽  
pp. 193-198 ◽  
Author(s):  
Bengtson ◽  
Simlick ◽  
Binette ◽  
Lovett ◽  
Alves ◽  
...  
1980 ◽  
Vol 95 (4) ◽  
pp. 472-478 ◽  
Author(s):  
A. Eugene Pekary ◽  
Jerome M. Hershman ◽  
Clark T. Sawin

Abstract. Basal serum TSH and the peak TSH response to a 500 μg TRH bolus were measured in 57 euthyroid and in 29 hypothyroid subjects either receiving graded thyroid hormone replacement or acutely removed from full replacement therapy. Serum TSH, total T4 and T3 were determined by sensitive radioimmunoassay methods. The peak versus basal TSH data for hypothyroid patients were linear within individuals. The regression slope of the peak versus basal TSH data for all hypothyroid subjects did not differ significantly from the corresponding slope for all euthyroid subjects. Basal and peak TSH versus T3 and T4 data for hypothyroid patients were also linear within each individual. Moreover, the regression of the basal TSH values averaged over the non-replacement to full replacement state against the TSH versus T3 slope had a significant negative correlation. This trend leads to an array of regression lines which average to the familiar hyperbolic relationship between thyrotrophin and thyroid hormone levels in man.


2011 ◽  
Vol 74 (3) ◽  
pp. 346-353 ◽  
Author(s):  
Sebastián Susperreguy ◽  
Liliana Muñoz ◽  
Natalia Y. Tkalenko ◽  
Ivan D. Mascanfroni ◽  
Vanina A. Alamino ◽  
...  

2008 ◽  
Vol 93 (4) ◽  
pp. 1172-1174 ◽  
Author(s):  
Irwin Klein ◽  
Sara Danzi

1995 ◽  
Vol 311 (2) ◽  
pp. 567-573 ◽  
Author(s):  
P Chiarugi ◽  
G Raugei ◽  
R Marzocchini ◽  
T Fiaschi ◽  
C Ciccarelli ◽  
...  

The modulation of expression of the skeletal muscle and erythrocyte acylphosphatase isoenzymes by thyroid hormone has been investigated. Our results indicate a differential regulation of the two enzymic isoforms by tri-iodothyronine (T3) in K562 cells in culture: an increase in the specific mRNA during T3-stimulation is shown only for the skeletal muscle isoenzyme. A fast and transient T3 induction of the accumulation of the specific mRNA can be observed, reaching a maximum 8 h after hormone treatment and then rapidly decreasing almost to the steady-state level after 24 h. A nuclear run-on assay was performed to explore the mechanisms of this regulation. These studies indicate that T3 induction of skeletal muscle acylphosphatase mRNA is due, at least in part, to a fast and transient increase in the rate of gene transcription, within 4 h after hormone administration. A very rapid decrease is then observed within a further 2 h. T3-dependent accumulation of the mRNA for the skeletal muscle acylphosphatase requires ongoing protein synthesis, as confirmed by inhibition with cycloheximide or puromycin. These findings indicate that the transcriptional regulation of the gene may be indirect.


2019 ◽  
Vol 76 (8) ◽  
pp. 1275-1294 ◽  
Author(s):  
Cecilia A. O’Leary ◽  
Timothy J. Miller ◽  
James T. Thorson ◽  
Janet A. Nye

Climate can impact fish population dynamics through changes in productivity and shifts in distribution, and both responses have been observed for many fish species. However, few studies have incorporated climate into population dynamics or stock assessment models. This study aimed to uncover how past variations in population vital rates and fishing pressure account for observed abundance variation in summer flounder (Paralichthys dentatus). The influences of the Gulf Stream Index, an index of climate variability in the Northwest Atlantic, on abundance were explored through natural mortality and stock–recruitment relationships in age-structured hierarchical Bayesian models. Posterior predictive loss and deviance information criterion indicated that out of tested models, the best estimates of summer flounder abundances resulted from the climate-dependent natural mortality model that included log-quadratic responses to the Gulf Stream Index. This climate-linked population model demonstrates the role of climate responses in observed abundance patterns and emphasizes the complexities of environmental effects on populations beyond simple correlations. This approach highlights the importance of modeling the combined effect of fishing and climate simultaneously to understand population dynamics.


1999 ◽  
Vol 202 (18) ◽  
pp. 2475-2484
Author(s):  
A.M. Schreiber ◽  
J.L. Specker

Salinity tolerance changes during larval development and metamorphosis in the summer flounder (Paralichthys dentatus) and other teleosts. The physiological mechanisms responsible for osmoregulation during these early stages of development are not well understood. This study characterized changes in ultrastructure, intracellular membranes and immunoreactive Na(+)/K(+)-ATPase of mitochondria-rich cells (MRCs) in the gills of summer flounder during metamorphosis. Gill ultrastructure at the start of metamorphosis revealed only one type of MRC, which had weak reactivity to osmium and lacked a well-defined apical pit. In juveniles, two types of MRCs were observed: light-staining MRCs (LMRCs) with weak reactivity to osmium, and dark-staining MRCs (DMRCs) with strong reactivity to osmium and positioned adjacent to LMRCs. Compared with MRCs at the start of metamorphosis, the mitochondria of juvenile MRCs appeared smaller, with more transverse cristae and electron-dense matrices. Changes in MRCs during metamorphosis were also accompanied by increased immunoreactive Na(+)/K(+)-ATPase. These findings suggest that gill MRCs develop during the metamorphosis of summer flounder as the gill takes on an increasingly important osmoregulatory role.


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