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Indian J Exp Biol. 2006 Aug;44(8):640-6.Links
Tri-iodo thyronine regulates antioxidant enzyme activities in different cell
fractions through a mechanism sensitive to actinomycin D in a teleost, Anabas
testudineus (Bloch).
Saumya SM, Sreejith P, Vijayasree AS, Divya L, Manju M,
Oommen OV.
Department of Zoology, University of Kerala, Kariavattom, India.
The present study evaluated the effects of hyperthyroid state on lipid
peroxidation and antioxidant enzymes in the crude (CF), post nuclear (PNF) and
mitochondrial fractions (MF) of the fish liver. The in vivo injection of T3
(200ng) did not change the lipid peroxidation products, malondialdehyde (MDA)
and conjugated dienes (CD), while actinomycin D (10microg), a potent mRNA
inhibitor when administered with T3 increased them. The antioxidant enzymes like
superoxide dismutase (SOD) and catalase (CAT), glutathione peroxidase (GPx) and
glutathione reductase (GR) had an increased activity in CF and MF of
hyperthyroid group to compete the increased oxidative stress, but actinomycin D
partially inhibited the T3-induced activity. SOD and CAT activities in PNF of
hyperthyroid group had no change, the glutathione concentration varied depending
on the GPx and GR activity. Hyperthyroidism decreased the protein content, while
simultaneous administration of actinomycin D inhibited the T3 action of
elevating the protein content. The results suggest that the antioxidant defense
status in A. testudineus is modulated by thyroid hormone, through an action
sensitive to actinomycin D.
PMID: 16924834
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