İsmail Özmen

Effects of metamizol and magnesium sulfate on enzyme activity of glucose 6-phosphate dehydrogenase from human erythrocyte in vitro and rat erythrocyte in vivo

OBJECTIVE Effects of metamizol and magnesium sulfate on erythrocyte glucose 6-phosphate dehydrogenase enzyme activity were investigated in in vitro and in vivo conditions. METHODS For in vitro studies, glucose 6-phosphate dehydrogenase was purified from human erythrocyte and rats were used for in vivo studies. Enzyme activity was determined according to the Beutler method by using a spectrophotometer at 340 nm. RESULTS The results of in vitro study showed that their mean K(i) values were 6.35 x 10(-3) M for metamizol and 1.32 x 10(-2) M for magnesium sulfate and their inhibition types were uncompetitive. I(50) value was 17 mM for metamizol and 50 mM for magnesium sulfate in in vitro study. In the case of in vivo studies, 200 mg/kg metamizol inhibited the enzyme activity by 40% during the first 1.5 h (p < 0.05), and 225 mg/kg magnesium sulfate significantly inhibited the enzyme activity throughout 24 h (p < 0.01). CONCLUSION The results of this study suggested that metamizol and magnesium sulfate have significant inhibition effect on the activity of glucose 6-phosphate dehydrogenase enzyme in both in vivo and in vitro.

Evaluation of effect of some corticosteroids on glucose-6-phosphate dehydrogenase and comparative study of antioxidant enzyme activities

Corticosteroids are anti-inflammatory drugs that are similar to the natural corticosteroid hormones produced by the cortex of the adrenal glands. The objective of this study was to scrutinize effects of some corticosteroids on glucose-6-phosphate dehydrogenase (G6PD) and some antioxidant enzymes. Initially, G6PD was purified from human erythrocytes by using ammonium sulphate precipitation and affinity chromatography. The two drugs, dexamethasone phosphate and prednisolone, investigated on the purified enzyme inhibited the enzyme activity. Comparative in vivo studies were performed to determine the effects of dexamethasone phosphate on the antioxidant enzyme activities using Spraque-Dawley rats. G6PD and catalase (CAT) activities were found significantly lower than in the control, whereas glutathione peroxidase (GP) activity was significantly increased in the erythrocytes of rats the receiving drug; glutathione reductase (GR) activity was unaffected. The results imply that dexamethasone phosphate may affect oxidative stress by changing antioxidant enzyme activities.

Effects of some antibiotics on activity of glucose-6-phosphate dehydrogenase from human erythrocytes in vitro and effect of isepamicin sulfate on activities of antioxidant enzymes in rat erythrocytes.

The purpose of this study was to investigate effects of some antibiotics on glucose-6-phosphate dehydrogenase (G6PD), antioxidant enzymes, and malondialdehyde (MDA). Initially, for in vitro studies, G6PD was purified from human erythrocyte, 9811-fold in a yield of 42.4% by using ammonium sulfate precipitation and 2′,5′ ADP-Sepharose 4B affinity gel. The purified enzyme showed a single band on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The effects of four different antibiotics (isepamicin sulfate, meropenem, chloramphenicol, and thiamphenicol glisinat hydrochloride) were investigated on the purified enzyme. Ki value and type of inhibition were determined by means of Lineweaver–Burk graphs and regression analysis graphs. Isepamicin sulfate inhibited the enzyme activity (I50 value, 2.1 mM; Ki value, 1.7 mM), whereas thiamphenicol glisinat hydrochloride activated the G6PD dose dependently. Other drugs showed no inhibition and activation effect. In addition, the effects of isepamicin sulfate on the activities of G6PD, glutathione reductase (GR), superoxide dismutases (SOD), glutathione peroxidase (GPx), catalase (CAT), and glutathione S-transferase (GST) and MDA contentrations were examined in Sprague-Dawley rat erythrocytes in vivo. A marked alteration in the activities of these enzymes and MDA levels may be the result of oxidative stress in the rats receiving isepamicin sulfate.

Investigation of Glucose 6-Phosphate Dehydrogenase (G6PD) Kinetics for Normal and G6PD-Deficient Persons and the Effects of Some Drugs

In the present study, blood samples from 1183 children aged 0.5–6 years were taken. Three children were found with G6PD deficiency by examining the enzyme activity and hemoglobin ratio. Some kinetic properties of glucose 6-phosphate dehydrogenase enzyme (G6PD) were studied after the purification of the enzyme with ammonium fractionation, dialysis and 2′,5′ ADP-Sepharose 4B affinity chromatography from a healthy person and from three G6PD-deficient people. The purity of the enzymes was confirmed by SDS-PAGE electrophoresis. The effects of some drugs which are known inhibitors of G6PD activity were studied. Some of the drugs stimulated the activity of the enzyme in two of the three cases with G6PD deficiency. KM values, Vmax values for G6P and NADP+, optimum pH and optimum temperature for the enzyme from the healthy person and the three G6PD-defficient people are reported.

The fatty acid content and composition of spinal cord and brain of rabbits receiving intrathecal ketamine

AbstractThe present study investigates the effects of intrathecal ketamine on the concentration and composition of fatty acids in blood-brain barrier (BBB) tissues of New Zealand male rabbits. Ketamine is a drug that produces analgesia following intrathecal injection. It is very well known that fatty acids (FAs) play an important role in membrane fluidity of BBB tissues, which control the transportation of substances into brain. The total cellular fatty acids in brain and three spinal cord sections (cervical, thoracic, lumbar) of rabbits with or without drug administration were determined by gas chromatography using the Sherlock software (Microbial ID, Newark, DE) with the eukary database of fatty acid methyl ester (FAME) profiles for eukaryotic cells (Sherlock version 4.0). The fatty acid profiles of three different spinal cord sections were quite similar, but different than those of brain tissues. There were 23–25 fatty acids in spinal cord sections and 11 in the brain tissues of control animals compare...