The purine metabolism of human erythrocytes.

This review summarizes currently available information about a crucial part of erythrocyte metabolism, that is, purine nucleotide conversions and their relationships with other conversion pathways. We describe the cellular resynthesis, interconversion, and degradation of purine compounds, and also the regulatory mechanisms in the conversion pathways. We also mention purine metabolism disorders and their clinical consequences.

The effect of new non-cross resistant antitumour agents on the energy state of human erythrocytes.

Multidrug resistance (MDR) of tumour cells is related to the overexpression of ATP-dependent pumps responsible for the active efflux of antitumour agents out of resistant cells. Benzoperimidine and anthrapyridone compounds exhibit comparable cytotoxic activity against sensitive and MDR tumour cells. They diffuse extremely rapidly across the plasma membrane and render the ATP-dependent efflux inefficient.

Purine nucleotides and their metabolites in erythrocytes of streptozotocin diabetic rats.

Objectives: In the present study it was tried to obtain a complete overview of purine nucleotide metabolism in erythrocytes of streptozotocin (STZ) induced diabetes mellitus rats.

Methods: Erythrocyte levels of the main nucleotides (ATP, ADP, AMP, GTP, GDP, GMP, IMP, NAD+, NADP+), nucleosides (Ado, Guo, Ino) and the base Hyp were measured using the HPLC method. The parameters that can be deduced from their concentrations: TAN, TGN and AEC, GEC expressed by the ratio of high/low energy nucleoside phosphates were calculated.

Effect of lead ions on rat erythrocyte purine content.

The influence of short-term exposure to lead on the energetic status of erythrocytes in rats is reported in this study. The male Wistar rats selected for this study drank water containing 1% lead(II) acetate and/or intraperitoneal injections of 1 or 2 mg/kg body wt every 4 d starting on the eighth of the experiment, over a period of 1 mo. The whole-blood lead concentration measured after 4 wk was 1.

The effect of lead ions on the energy metabolism of human erythrocytes in vitro.

The aim of this work was to evaluate the influence of chronic exposure to lead ions on the parameters of energetic status of human erythrocytes in vitro. Umbilical cord erythrocytes were incubated with lead acetate at final lead ion concentrations ranging from 10 to 200 microg/dl. ATP, ADP, AMP, adenosine, GTP, GDP, GMP, guanosine, IMP, inosine, hypoxanthine, NAD and NADP concentrations in erythrocytes were determined using HPLC.

[The impact of lead ions on metabolism of erythrocytes].

Lead contamination of the environment constitutes one of the major ecological problems. The determination of blood lead concentration is essential for evaluating lead exposure. Lead ions result in changes in the activity of numerous enzymes, disturb metabolic pathways of cells (inhibition of glycolysis), and inhibit synthesis of haem and globin.

[Calcium and magnesium in the blood serum of workers exposed to fluorine compounds, in relation to age and duration of employment].

The study included controls and those exposed to fluorine compounds. In the exposed group a highly statistically significant increase in calcium concentration was found, as compared to the control group. On the other hand, the level of magnesium was the same in both groups.

[Blood serum content of zinc, copper and iron in workers exposed to fluorine compounds, depending on age and length of employment].

The content of zinc, copper and iron was analysed in the blood serum of those exposed to fluorine compounds. The concentration of copper and iron was found to be highly statistically significant in those people, as compared with the controls.

Certain phosphate compounds in the erythrocytes of patients with primary hyperlipidaemia.

The investigations were carried out in 30 patients with primary hyperlipidaemia (hypercholesterolaemia, hypertriglyceridaemia and mixed form). The serum total cholesterol and triglycerides, and in the erythrocytes the levels of AMP, ADP, ATP, ATP complex with Fe, MP, HDP and DGP were determined. Twenty blood donors served as a control group.

Effect of UV-irradiation in vitro on adenin nucleotides metabolism, Na+ and K+ concentration, osmotic properties and submicroscopic structure of pigeon red blood cells.

Effect of UV-irradiation in vitro on metabolism of adenine nucleotides: ADP, ATP and AXP, osmotic properties and submicroscopic structure of nucleated pigeon red blood cell was investigated. Irradiation carried out for 60, 120, 180, 240 and 300 minutes. Hanau S-500 lamp with efficiency 4.