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 literature is fragmentary because studies have concentrated only on selected aspects of purine metabolism; hence the need for a synthetic approach.

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. The effects of streptozotocin-induced diabetes on the concentration and metabolism of rat erythrocyte purine and pyridine nucleotides and the activity of Na+, K+-ATPase as well as Ca2+-ATPase were investigated. RESULTS: Increased dephosphorylation of adenine nucleotides (found as the increased concentration of Ado and Hyp and the decrease in AEC value) and the decrease in ATP and TAN and the changes in the concentrations of NAD+ and NADP+ suggest serious purine and pyridine metabolism disruptions in diabetic erythrocytes and decrease in ATPases activity. CONCLUSION: The observations suggest that purine nucleotide degradation is markedly accelerated in erythrocytes of STZ diabetic rats.

[The impact of lead ions on metabolism of erythrocytes]. / Wplyw jonów olowiu na metabolizm erytrocytów.

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. However, the activity of lead via pathological formation of free radicals is thought to be one of the most important molecular mechanisms of lead toxicity. Based on available literature, the issues concerning the effect of lead on metabolism of erythrocytes is discussed in this paper.

[Blood serum content of zinc, copper and iron in workers exposed to fluorine compounds, depending on age and length of employment]. / Zachowanie sie cynku, miedzi i zelaza w surowicy krwi ludzi narazonych na dzialanie zwiazków fluoru, w zaleznosci od wieku i stazu pracy.

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.

[Calcium and magnesium in the blood serum of workers exposed to fluorine compounds, in relation to age and duration of employment]. / Zachowanie sie wapnia i magnezu w surowicy ludzi narazonych na dzialanie zwiazków fluoru, w zaleznosci od wieku i stazu pracy.

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.

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. The obtained results showed a statistically highly significant rise in ADP concentration in all investigated subgroups of hyperlipidaemic subjects, and a non-significant quantitative shift of other determined phosphate compounds.