[Effect in vitro of albendazole on the kinetics of cytosolic glutathione transferase from the rat liver].

INTRODUCTION

Since the idea of multifunctional mode of action of anthelmintics is considered and in experimental trichinellosis in vivo albendazole seems to act as an allosteric activator of cytosolic GST from mice muscles, in this study a termosensitivity after in vitro incubation with albendazole of purified commercial cytosolic glutathione transferase (GST) from the rat liver was investigated.

METHODS

Two extremal temperatures: -80 degrees C and +30 degrees C were used to destroy the dimer in quaternary structure of this enzyme.

RESULTS

In control preparations both extremal temperatures destroy this structure, so the Michaelis-Menten kinetic curves of substrate saturation show the typical hyperbolic shape. After a long (15 h) freezing at -80 degrees C or heating (up to 14 h at +30 degrees C) the kinetics of substrate saturation of GST after incubation with albendazole show the sigmoidal or "double sigmoidal" shape, pointing out the quaternary GST structure as a complex of "frozen subunits". Drug inhibits about 6-times the total activity of GST after incubation at +30 degrees C. We conclude that albendazole in vitro influences the structure of cytosolic GST from the rat liver and inhibits its activity, but, in opposite to in vivo study in mouse muscles infected with Trichinella spiralis larvae, does not act as an activator of this enzyme.