Tag Archives: isozymes

Activity and isozyme content of lactate dehydrogenase under long-term oral taurine administration to rats

R. D. Ostapiv1,2, S. L. Humenyuk2, V. V. Manko1

1Ivan Franko National University of Lviv, Ukraine;
2SSRCI of Veterinary Medicinal Products and Feed Additives, Lviv, Ukraine;
e-mail: romostapiv@gmail.com; vvmanko@lnu.edu.ua

The effect of long-term oral taurine administration to rats on activity of lactate dehydrogenase (LDH), its isozyme content and activity in the whole blood, liver, thigh muscle, brain and testes tissues were studied in the present work. For this purpose male Wistar rats with body weight 190–220 g were randomly divided into three groups, they were orally administered drinking water (control group) or taurine solution 40 and 100 mg per kg of body weight ( groups I and II, respectively). The total lactate dehydrogenase activity was measured spectrophotometrically, the percentage content of isozymes was determined by electrophoresis in 7.5% poliacrylamide gel with further staining according to J. Garbus. It was found that the total lactate dehydrogenase activity increased in all studied tissues. In testes of animals of both groups and in brain of group I animals, the total percentage contents of isozymes that are responsible for lactate production (LDH4+LDH5) increased. In liver of animals of both groups and in whole blood of group II animals, the total percentage content of isozymes that produce pyruvate (LDH1+LDH2) increased. In thigh muscle of both groups and in brain of group II animals the balance between LDH1+LDH2 and LDH4+LDH5 content did not differ from control values, though total lactate dehydrogenase activity was significantly higher, than that in the control group. Thus, the increase in the lactate dehydrogenase activity under long-term oral taurine administration in different rat tissues was found to be tissue- and dose-dependent and was caused by the increase in the content of different isozymes. Such increase in group I animals might be explained by adaptive mechanisms to hypoxia caused by high doses of taurine. For group II animals high doses of taurine were toxic and directly affected metabolic processes in the animal bodies.

Structure and functions of glutathione transferases

O. M. Fedets

Stepan Gzhytskyi Lviv National University of Veterinary Medicine and Biotechnologies, Ukraine;
e-mail: olehfedets@gmail.com

Data about classification, nomenclature, structure, substrate specificity and role of many glutathione transferase’s isoenzymes in cell functions have been summarised. The enzyme has been discovered more than 50 years ago. This family of proteins is updated continuously. It has very different composition and will have demand for system analysis for many years.