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Restoration Of Tryptophan Hydroxylase Functions And Serotonin Content In The Atlantic Croaker Hypothalamus By Antioxidant Treatment During Hypoxic Stress, Md. Saydur Rahman, Peter Thomas
Restoration Of Tryptophan Hydroxylase Functions And Serotonin Content In The Atlantic Croaker Hypothalamus By Antioxidant Treatment During Hypoxic Stress, Md. Saydur Rahman, Peter Thomas
School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations
Antioxidants are prototypical scavengers of oxygen-free radicals and have been shown to prevent neuroendocrine dysfunction in vertebrates during oxidative stress. In the present study, we investigated whether antioxidant treatment can reverse hypoxia-induced down-regulation of hypothalamic tryptophan hydroxylase (TPH) and serotonergic functions in Atlantic croaker. Hypothalamic neuronal contents of TPH-1 and TPH-2 proteins, serotonin (5-hydroxytryptamine, 5-HT) and its precursor, 5-hydroxytryptophan (5-HTP) as well as hypothalamic TPH-1 and TPH-2 mRNA expression and TPH activity were measured in croaker after exposure to hypoxia and treatment with pharmacological agents. Multiple injections of N-ethylmaleimide, a sulfhydryl alkylating agent, caused comparable decreases in hypothalamic TPHs functions …
Influence Of Constant And Periodic Experimental Hypoxic Stress On Atlantic Croaker Otolith Chemistry, John Mohan, Md. Saydur Rahman, Peter Thomas, Benjamin Walther
Influence Of Constant And Periodic Experimental Hypoxic Stress On Atlantic Croaker Otolith Chemistry, John Mohan, Md. Saydur Rahman, Peter Thomas, Benjamin Walther
School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations
The chemical composition of fish otoliths may provide information on the environmental exposure histories of fishes if ‘vital effects’ on element incorporation are minimal. In order to use redox-sensitive geochemical proxies, such as manganese, in otoliths to quantify sublethal exposure to hypoxia, the relative influence of endogenous and exogenous controls on otolith composition must first be validated. Controlled laboratory experiments were conducted on Atlantic croaker Micropogonias undulatus to examine the response of otolith Sr:Ca, Ba:Ca, Mg:Ca, Mn:Ca, and Na:Ca ratios to either constant or periodic hypoxia treatments for 4 and 10 wk, respectively. Although fish somatic growth and condition were …