PubMed Health⌕ Search

Biomedical subjects

M Kostić

Publications and source records attributed to M Kostić.

At least 37 records · Page 2Linked to original sources
PubMed1990

Aldehyde and nucleotide separations by high-performance liquid chromatography. Application to phenylhydrazine-induced damage of erythrocytes and reticulocytes.

High-performance liquid chromatographic (HPLC) techniques were used for the determination of aldehydes as lipid peroxidation products and of nucleotide concentrations in rabbit red blood cells exposed to phenylhydrazine hydrochloride. Aldehydes were determined by derivatization to dinitrophenylhydrazones, followed by thin-layer chromatographic and HPLC separation with methanol-water on an ODS column. Nucleotides and their derivatives were measured by ion-pair reversed-phase HPLC gradient elution with 10 mM ammonium phosphate buffer containing 2 mM tetrabutylammonium phosphate on ODS columns. The sensitivity of mature erythrocytes was compared with that of reticulocytes against the toxicological effects of phenylhydrazine. For both cell types an increase in aldehyde concentrations, especially of 4-hydroxynonenal, and a decline in both energy-rich nucleoside triphosphate and NAD+ were demonstrated.

Aldehydes↗
PubMed1981

Effects of dibutyryl-cANP on glycolysis in washed human erythrocytes.

The experiments were carried out with washed human erythrocytes in order to study the effects of dibutyryl-cAMP (DB-cAMP) on glycolysis. 5 mM DB-cAMP significantly increases glucose consumption and lactate production in incubated erythrocytes. The cross-over plot of glycolytic intermediates shows that increased glycolysis is probably the result of activation of phosphofructokinase by DB-cAMP. Under the same condition DB-cAMP significantly protects the 2,3-diphosphoglycerate level in incubated erythrocytes.

2,3-Diphosphoglycerate↗
PubMed1981

[The role of cAMP in the energy metabolism of human erythrocytes].

In human red blood cell there is complete adenyl cyclase--cAMP system. However, the role of this system and its connection with energy metabolism in red cell is not known. Hence, we studied the effects of cAMP and DB-cAMP on energy metabolism in human red cell. Blood was taken out from haematologically healthy volunteers. Red cells were isolated by differential centrifugation and washed three times in Tris-Ringer buffer (pH 7.4). The red cells suspensions (in the above buffer) were simultaneously incubated without additions (control) and with cAMP or DB-cAMP (5 mmol/L). Incubation temperature was 37 degrees C. The samples of suspensions for the extraction of metabolites and cofactors were taken at 0 and 180 minutes of incubation. The lactate, glucose, G6P, F6P, TP, ATP, ADP and AMP were determined in neutralized perchloric acid extracts by specific enzymatic methods. Results of our experiments show that cAMP and DB-cAMP significantly increase red cell glycolysis. Under the same conditions these nucleotides induce positive "cros-over" point at the phosphofructokinase (PFK) step of the glycolysis. The levels of adenine nucleotides (ATP, ADP, AMP) were unchanged through a whole period of incubation. We concluded that cAMP and DB-cAMP stimulates glycolytic process in red cells probably by allosteric activation of PFK.

Adenine Nucleotides↗