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Thyroxine influence on different ion‐specific adenosine triphosphatase activities in fat body of Bombyx mori during development
Author(s) -
Reddy K. Damodar,
Chaudhuri Anathbandhu
Publication year - 1998
Publication title -
archives of insect biochemistry and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.576
H-Index - 66
eISSN - 1520-6327
pISSN - 0739-4462
DOI - 10.1002/(sici)1520-6327(1998)37:3<191::aid-arch1>3.0.co;2-w
Subject(s) - medicine , endocrinology , biology , instar , bombyx mori , enzyme assay , metamorphosis , enzyme , larva , pupa , atpase , biochemistry , ecology , gene
The effects of thyroxine on the activity of different ATPases (Na + ‐K + , Ca 2+ , and Mg 2+ ) in fat body cells of the silkworm, Bombyx mori, were investigated during different developmental stages. In both sexes the maximum enzyme activity was observed in the fat body cells of day 7 last instar larva (the day before spinning). Na + ‐K + , Ca 2+ ‐, and Mg 2+ ‐ATPase activity in the fat body markedly declined after pupation and continued to decrease in day 1 adults. Injection of thyroxine (T4) at doses of 1.0 and 2.0 μg/g during fifth instar significantly elevated all ATPase activities in the larval, pupal, and adult stages in both sexes. At a dose of 0.5 μg/g, T4 had no effect on day 2 fifth instar larva, although it increased the ATPase activity at the other stages investigated. A higher dose (3.0 μg/g) caused a significant reduction in enzyme activity in all stages with the exception of day 2 fifth instar larva. Thus, the repression of enzyme activity with the higher dose and the elevation of enzyme activity with the lower dose establish the biphasic nature of T4 action on the ATPase system in fat body cells of the silkworm. Arch. Insect Biochem. Physiol. 37:191–196, 1998. © 1998 Wiley‐Liss, Inc.