Biomedical subjects

T Grune

Publications and source records attributed to T Grune.

132 records · Page 8Linked to original sources

PubMed1990

Nucleotide and glutathione status in erythrocytes of children undergoing chronic hemodialysis under erythropoietin treatment.

Recombinant human erythropoietin (rhEPO) used for the treatment of children with renal anemia is an effective stimulus of erythroid proliferation and differentiation. The increases of reticulocytes and of the hematocrit values give the possibility to renounce further blood transfusions in dialysis patients. There are no beneficial in vivo effects of rhEPO on the glutathione status and on the nucleotide contents of red blood cells. Therefore, indices for stabilizing effects of rhEPO on the circulating red blood cells cannot be due to glutathione and nucleotide metabolism.

Adolescent↗

PubMed1990

Metabolism of purine and pyrimidine compounds in erythrocytes of tumor-bearing mice.

The pattern of purine and pyrimidine derivatives was studied in the erythrocytes of C3HA and ICR mice during Hepatoma 22 and Ehrlich ascites tumor cell growth. Concentrations of purine nucleotides, nucleosides and nucleobases of host erythrocytes were changed after the implantation of the tumors. The host erythrocytes markedly concentrated adenine and guanine nucleotides both during logarithmic and plateau phase of tumor growth (5th and 11-12th days after inoculation of the tumor). The contents of nucleosides and nucleobases in the red blood cells were decreased during the logarithmic growth phase but restored within the plateau phase.

Animals↗

PubMed1989

Regulation of purine nucleotide metabolism in hypoxic liver and intestine of rats: radical scavenging effects of allopurinol and oxypurinol.

The relationship between nucleotide catabolism and generation of activated oxygen species was investigated in liver, hepatocytes and small intestine of rats. In severe hypoxia nucleotide degradation via xanthine oxidase and urate oxidase requires about half of the oxygen consumed. Data on the changes of nucleobase compounds in rat hepatocytes and small intestine during ischemia and reoxygenation and the effects of allopurinol and oxypurinol thereon are presented. From EPR measurements it is concluded that OH. radicals induce reactions of allopurinol yielding long-living products which are able to react with DMPO-OH with loss of its radical properties.

Allopurinol↗

PubMed1989

Nucleotide concentrations in hepatocytes during anoxia and reoxygenation in presence of allopurinol and oxypurinol.

In hepatocytes of starved rats nucleotide, nucleoside and nucleobase concentrations were measured during and following anoxia. A complete restoration of ATP is observed during reoxygenation after anoxic periods less than 60 minutes. GTP cannot be completely restored after 30 minutes of anoxia. Allopurinol and oxypurinol do not accelerate the ATP and GTP restoration. IMP, adenosine and AMP concentrations are increased in presence of allopurinol or oxypurinol during anoxia and reoxygenation.

Adenosine Triphosphate↗

PubMedDate not supplied

LPS-induced protein oxidation and proteolysis in BV-2 microglial cells.

Exposure of proteins to oxidants leads to increased oxidation followed by preferential degradation by the proteasomal system. The role of the biological oxidant production in microglial BV-2 cells in the oxidation and turnover of endogenous proteins was measured. It could be demonstrated, that BV-2 cells are relatively resistant to fluxes of oxidants, but nevertheless protein oxidation occurs due to activation by LPS. This protein oxidation is followed by an enhanced degradation of endogenous proteins. Using PBN, a free radical scavenger and antioxidant, we could demonstrate the involvement of free radicals in the increased proteolysis in BV-2 cells after LPS-treatment. A slight but significant up-regulation of the proteasomal system after LPS activation takes place, indicating the importance of his proteolytic system in the maintenance of the protein pool of microglial cells.

Animals↗

PubMedDate not supplied

Metabolic rates of 4-hydroxynonenal in tubular and mesangial cells of the kidney.

The degradation of the lipid peroxidation product 4-hydroxynonenal (HNE) in primary cultures of kidney tubular and mesangial cells was determined. Using various initial concentrations of the aldehyde a decline of cellular viability was found. Mesangial cells were more susceptible to the toxic effects of HNE. In consumption studies of HNE the decline of the exogenously added aldehyde was comparable in both cell types after addition of 10 and 1 micromol HNE/l. After addition of 100 micromol/l aldehyde a drastically lower HNE degrading capacity was found in mesangial cells as compared to tubular cells. The loss in the HNE degrading capacity was accompanied by an increased formation of HNE-protein aggregates as demonstrated by immunoblots. Therefore, we concluded that the low ability of mesangial cells to degrade HNE may be a factor of the toxicity of free radicals on the kidney.

Aldehydes↗