Open AccessComparative analysis of tryptophan oxygenase activity and glucocorticoid receptor under the influence of insulin
Author(s) -
Isenović Er,
Zorica Žakula,
Goran Korićanac,
N Ribarac-Stepić
Publication year - 2008
Publication title -
physiological research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.647
H-Index - 70
eISSN - 1802-9973
pISSN - 0862-8408
DOI - 10.33549/physiolres.931135
Subject(s) - glucocorticoid , glucocorticoid receptor , medicine , endocrinology , insulin , chemistry , receptor , tryptophan , insulin receptor , biology , insulin resistance , biochemistry , amino acid
This investigation addresses the interaction of insulin (INS) andglucocorticoid (GC) signaling in the hepatic regulation oftryptophan oxygenase (TO) enzyme activity in the rat. MaleWistar rats (200-250 g b.w) received an injection of the differentdoses of INS (10, 25, 50, 70 and 100 μg/200 g b.w., i.p.) andwere used for experiments 3 h and 18 h after INS administration.This study shows that maximum of TO activity was found at doseof 50 μg of INS with peak increases observed at 3 h and 18 hafter injection of INS, while INS had no effect on TO activity inadrenalectomized rats. The analysis of INS effects onglucocorticoid receptor-complex (GC/GR complex) stability showsthat complexes from INS-treated rats are less stable than thosefrom control animals. In addition, INS-stimulated stability ofglucocorticoid receptor (GR) protein was significantly increasedfrom the controls. Furthermore, the results show that GC/GRcomplexes from INS-treated rats could be activated andaccumulated at higher rate in cell nuclei of control animals.These data support the involvement of INS in modulation of GCsignaling pathway which mediates, in part, the activity of TO.