Accessible Requires Authentication Published by De Gruyter January 14, 2013

Dexamethasone decreases the spermidine and spermine concentrations and polyamine oxidase activity in rat thymus

Gordana Bjelaković, Dusica Pavlovic, Gordana Kocic, Ivana Stojanović, Tatjana Jevtović-Stoimenov, Jelenka Nikolić, Dusan Sokolovic and Jelena Basic

Abstract

Background: Glucocorticoids (GCs) exert a wide range of anti-inflammatory, immunosuppressive, and antineoplastic activities. The aim of our investigation was to elucidate the effect of dexamethasone, a synthetic GC, on polyamine metabolism in the rat thymus.

Methods: Male albino Wistar rats, weighing 180–230 g, were divided into two groups: control and experimental. The experimental group received dexamethasone intraperitoneally for 3 days, in a daily dose of 4 mg/animal. The last dose of the hormone was applied on the 3rd day, 1 h before killing. The control group received 0.9% NaCl instead of the hormone. The animals were killed by decapitation. The thymus was removed quickly and rinsed with ice-cold saline. Polyamines were extracted using butanol. The amount of polyamines was investigated by electrophoresis. For the estimation of polyamine oxidase (PAO) activity, 10% water homogenate was prepared.

Results: Our results suggested that dexamethasone supplementation of experimental animals for 3 days significantly decreased the spermine (Sp) and spermidine (Spd) levels in rat thymus tissue (Sp Control, 362.56±25.33 nmol/g wet weight; Sp Exp. Group, 313.01±21.16 nmol/g wet weight; Spd Control, 673.81±30.95 nmol/g wet weight; Spd Exp. Group, 410.21±17.26 nmol/g wet weight). PAO activity significantly decreased under hormone influence in comparison with the control group (PAO Control, 0.449±0.121 U/mg prot.; PAO Exp. Group, 0.312±0.096 U/mg prot.).

Conclusions: The decrease in polyamine amounts in the rat thymus is not due to the change in PAO activity.


Corresponding author: Prof. Dr. Gordana Bjelakovic, Faculty of Medicine, Institute for Biochemistry, University of Niš, Blvd. dr Zorana Djindjica 81, 18000 Niš, Serbia

Received: 2012-9-1
Accepted: 2012-11-22
Published Online: 2013-01-14
Published in Print: 2013-02-01

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