We have examined the effect of ambient water temperature on the ability of juvenile rainbow trout to respond to estradiol (E2) injection with vitellogenin (Vg) synthesis. Vg appeared in serum within 24 hr of E2 injection in fish kept at 15 degrees and rose to 70 mg/ml over a 10-day treatment period during which four injections of E2 were given. A group of fish kept at 9 degrees responded more slowly to the same multiple injection protocol and showed Vg accumulation of only 8.9 mg/ml on the 10th day. Hepatic Vg mRNA levels accumulated more rapidly and extensively in animals treated and kept at 15 degrees than at 9 degrees; however, differences in serum Vg concentrations could not simply be attributed to differences in Vg mRNA levels. The ratio of serum Vg:Vg mRNA increased steadily over the treatment period, especially in the 15 degrees group, suggesting greater efficiency or capacity for translation and/or processing of the Vg protein at the higher temperature. Examination of hepatic nuclear estrogen receptor (ER) concentrations revealed a three- to five-fold increase in high-affinity E2-binding activity within the first 24 hr after injection in both temperature groups. Nuclear ER levels remained elevated to roughly the same extent in both groups throughout the 10-day period. Differences in nuclear ER concentrations and serum E2 concentrations could not account for the large differences in Vg mRNA and protein levels between the two temperature groups. Furthermore, a single injection of E2 at 15 degrees was able to induce higher levels of Vg mRNA and protein than multiple injections at 9 degrees. We suggest that temperature modulates the responsiveness of the liver to E2 at stages which are independent of E2 or ER concentrations.
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http://dx.doi.org/10.1006/gcen.1993.1031 | DOI Listing |
Sci Rep
January 2025
Nanotechnology Department, Faculty of Science, Urmia University, Urmia, Iran.
Today, active packaging has become essential to increase food safety and decrease food spoilage. In this study, the aim was to delay spoilage and increase the shelf life of rainbow fish fillets with a new hybrid nanocomposite active packaging. Packaging was fabricated with Ethylene vinyl acetate and active compounds such as rosemary extract, zinc oxide nanoparticles, and modified iron (Fe-MMT).
View Article and Find Full Text PDFEnviron Toxicol Chem
January 2025
Department of Environmental Toxicology, Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland.
Given the need to reduce animal testing for environmental risk assessment, we aim to develop a fish invitrome, an alternative fish modular framework capable of predicting chemical toxicity in fish without the use of animals. The central module of the framework is the validated RTgill-W1 cell line assay that predicts fish acute toxicity of chemicals (Organization for Economic Cooperation and Development Test Guideline (OECD TG) 249). Expanding towards prediction of chronic toxicity, the fish invitrome includes two other well-advanced modules for chemical bioaccumulation/biotransformation and inhibition of fish growth.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
Research Institute for Farm Animal Biology, Dummerstorf, Germany.
Human activities and climate change have significantly increased humic substances in freshwater ecosystems over the last few decades. This increase is particularly concerning during seasonal changes or after heavy rainfall, when concentrations can easily increase up to tenfold. This phenomenon, known as "browning," has unknown consequences for aquatic organisms.
View Article and Find Full Text PDFCell Biol Toxicol
January 2025
Department of Environmental Toxicology, Swiss Federal Institute of Aquatic Science and Technology, Eawag, 8600, Dübendorf, Switzerland.
Advancing in vitro systems to address the effects of chemical pollution requires a thorough characterization of their functionalities, such as their repertoire of biotransformation enzymes. Currently, knowledge regarding the presence, activity magnitudes, and inducibility of different biotransformation pathways in vitro is scarce, particularly across organs. We report organ-specific kinetics for phase I and II biotransformation enzymes, under basal and induced conditions, in two in vitro systems using salmonid fish: S9 sub-cellular fractions from brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss) were compared with rainbow trout cell lines.
View Article and Find Full Text PDFMar Biotechnol (NY)
January 2025
Department of Aquatic Life Medicine, Pukyong National University, Busan, 48513, South Korea.
Vibriosis caused by Vibrio anguillarum has been an important bacterial disease in cultured rainbow trout (Oncorhynchus mykiss). In the present study, we evaluated the protective efficacy of a vaccine that consists of formalin-killed (FK) V. anguillarum and the alr genes knockout auxotrophic-live (AL) V.
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