PubMed Health⌕ Search

Biomedical subjects

F O Belzer

Publications and source records attributed to F O Belzer.

At least 145 records · Page 8Linked to original sources

Changes in glutathione concentration in hypothermically perfused dog kidneys.

A loss of glutathione from the kidney can cause increased sensitivity to oxygen free radical-induced injury. In this study we investigated the effects of kidney preservation on glutathione and how various glutathione precursors affect glutathione concentration in the dog kidney. During 5-day continuous machine perfusion of the kidney at 5 degrees C, a loss of glutathione from the cortex tissue was seen (24% +/- 1% glutathione remained after 5 days). Perfusion with reduced glutathione (GSH, 3 mmol/L) suppressed this loss (77% +/- 11% of glutathione remained after 5 days). Oxidized glutathione (GSSG) did not prevent the loss of glutathione. The addition of the three amino acids that make up glutathione (glycine, glutamic acid, and cysteine, 3 mmol/L each) also suppressed the loss of glutathione (82% +/- 13% remained at 5 days). The glutathione precursor, thioproline, a cysteine delivery compound, in combination with glycine and glutamic acid (3 mmol/L each), stimulated the synthesis of glutathione in the kidney during hypothermic perfusion (137% +/- 23% of control values at 5 days). The increase in tissue glutathione stimulated by GSH or other precursors was sensitive to the glutathione synthetase inhibitor, buthionine sulfoximine. This indicated the existence of active glutathione metabolism even at 5 degrees C in perfused kidneys. This study showed that in kidney preservation a loss of glutathione occurred that could be suppressed by the addition of various precursors for glutathione synthesis. The loss of glutathione from preserved kidneys may be one cause of posttransplant renal injury that could be prevented by use of the appropriate glutathione precursors.

Animals↗

Hypothermic preservation of hepatocytes. III. Effects of resuspension media on viability after up to 7 days of storage.

Hepatocyte suspensions provide a rapid method to determine how hypothermic storage affects liver cell metabolism and viability. Using these studies, improved methods of hypothermic liver preservation for transplantation may be developed. In this study, rat hepatocytes were cold-stored for up to 7 days in University of Wisconsin liver preservation solution. At the end of each day of storage hepatocytes were resuspended in Krebs-Henseleit buffer or tissue-culture medium (Liebovitz-15; Fischer's; modified Fischer's, which was similar to Fischer's but with glycine and cysteine added; or Waymouth's medium). Hepatocyte viability was assessed by rewarming and oxygenating the suspensions and measuring the percentage of leakage of lactate dehydrogenase from the cells, the cellular concentration of potassium and the stimulation of respiration by succinate, all measures of plasma membrane integrity. Additionally, concentrations of ATP and glutathione after rewarming and reoxygenation in the various resuspension media were measured. Hepatocyte permeability to lactate dehydrogenase did not increase during cold storage of 1 to 7 days (7.2% +/- 2% leakage), indicating that most of the hepatocytes remained viable during cold storage. However, when rewarmed, loss of viability (leakage of lactate dehydrogenase) was dependent on the composition of the resuspension media. In Krebs-Henseleit buffer, viability was reduced after 2 and 3 days of storage (lactate dehydrogenase leakage on rewarming = 70% to 90%). Leakage of lactate dehydrogenase was reduced significantly after resuspension in tissue-culture media. After 6 days of storage, lactate dehydrogenase leakage from hepatocytes stored in Liebovitz- 15 or modified Fischer's was only about 30%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗

Current status of organ preservation with University of Wisconsin solution.

A retrospective analysis of all organs that were preserved with University of Wisconsin solution was undertaken to assess the impact of this solution on early allograft function. From May 1987 until June 1990, 181 livers, 92 pancreata, and 92 kidneys were preserved with University of Wisconsin solution for extended periods of time. The mean (+/- SD) preservation times were as follows: liver, 12.6 +/- 4.5 hours; pancreas, 16.7 +/- 4.4 hours; and kidney, 18.3 +/- 4.3 hours. The overall rate of primary nonfunction and hepatic artery thrombosis were 6.1% and 3.9%, respectively. No differences in the rates of primary nonfunction and hepatic artery thrombosis were noted for combined liver-pancreas procurement vs isolated liver retrievals or when reduced-size liver transplants were compared with nonreduced liver transplants. Likewise, no difference in primary nonfunction or hepatic artery thrombosis was seen in livers that were preserved for less than 6, 6 to 12, and greater than 12 hours. However, serum aminotransferase levels and prothrombin times were lower on the first postoperative day in livers that were preserved for less than 6 hours when compared with 6 to 12 or greater than 12 hours. Early pancreatic allograft function was also excellent for up to 24 hours of cold-storage preservation. All patients were immediately insulin independent, and there were no cases of initial nonfunction or graft pancreatitis. There were only two cases (2.2%) of pancreatic vascular thrombosis in this series. No difference in pancreatic function was noted for organs that were preserved for less than 6, 6 to 12, or greater than 12 hours. Likewise, renal allograft function was excellent, with only two patients (2.2%) requiring postoperative hemodialysis. The actuarial 1-month patient survival for liver and pancreas-kidney transplant recipients was 91.5% and 98.9%, respectively. Actuarial 1-month allograft survival for liver, pancreas, and kidney transplants was 83.0%, 96.7%, and 97.8%, respectively. In conclusion, University of Wisconsin solution represents a significant advancement in cold-storage organ preservation and is ideally suited as a universal intra-abdominal aortic-flush and cold-storage solution.

Adenosine↗