Glucose Stimulation of Cytochrome C Reduction and Oxygen Consumption as Assessment of Human Islet Quality

Sweet, Ian R.; Gilbert, Merle L.; Jensen, Rich; Sabek, Omaima; Fraga, Daniel; Gaber, A. Osama; Reems, Jo‐Anna

doi:10.1097/01.tp.0000178381.35014.37

Cited by 44 publications

(66 citation statements)

References 43 publications

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“…Thus DNA quantification is not necessary for this assay, while it is crucial for some recently proposed methods for estimating islet quality and potency, i.e. the analysis of oxygen consumption (16,17) and the analysis of total ATP amount (18,19). Theoretically, calculating the ADP/ATP ratio should be a more sensitive technique than measurement of the absolute ATP/DNA content, since ATP is converted to ADP at times of not fully compensated energy consumption.…”

Section: Discussionmentioning

confidence: 99%

The ADP/ATP Ratio: A Novel Predictive Assay for Quality Assessment of Isolated Pancreatic Islets

Goto

Holgersson

Kumagai‐Braesch

et al. 2006

American Journal of Transplantation

106

101

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The current standard assays for islet product release criteria are unable to predict the outcome after clinical islet transplantation. Therefore, establishment of reliable and rapid assays enabling pre-transplantation prediction of islet potency is warranted. In the present study, we have evaluated the adenosine diphosphate (ADP)/adenosine triphosphate (ATP) test, the glucose-stimulated insulin release, the loss of islets during the first 24 h in culture, and the insulin/deoxyribonucleic acid as predictive assays for the ability of isolated porcine islets to cure athymic mice with streptozotocin-induced diabetes. From the results presented, it is concluded that the measurement of the ADP/ATP ratio was the only test that correlated with transplantation outcome. In summary, we propose that the ADP/ATP assay is worthwhile as applied to human islet transplantation and seek to validate it as a rapid and potent predictor of transplant outcome.

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Section: Discussionmentioning

confidence: 99%

The ADP/ATP Ratio: A Novel Predictive Assay for Quality Assessment of Isolated Pancreatic Islets

Goto

Holgersson

Kumagai‐Braesch

et al. 2006

American Journal of Transplantation

106

101

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show abstract

“…However, the viability assay used in this study is subjective and lacks precision in discriminating differences between islet preparations. Further studies utilizing new technologies for islet quality assessment (22)(23)(24) are warranted to analyze the optimal enzyme dosages. An inherent problem with the method of counting IE is that it is operator dependent and prone to error because the actual shape of the islet is not always spherical.…”

Section: Discussionmentioning

confidence: 99%

Enhancing the Success of Human Islet Isolation Through Optimization and Characterization of Pancreas Dissociation Enzyme

Kin

Zhai

Murdoch

et al. 2007

American Journal of Transplantation

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A major obstacle to successful human islet isolation has been the variability of the enzymatic digestion phase. The aim of this study was to define optimal enzyme activity ranges normalized by the pancreas weight and to identify valid parameters for the optimal selection of successful lots of collagenase enzyme blends. Our results from 251 islet isolations showed that optimization of thermolysin dosage based on Caseinase unit/g pancreas contributed considerably to islet isolation outcome but that collagenase dosage measured by the manufacturer (Wünsch unit/g pancreas) was not a major determinant of islet isolation outcome. We also found that lot-to-lot inconsistency of enzyme performance was not explained by the activity values provided by the manufacturer, but rather by an in-house assay of class I collagenase (CI) and class II collagenase (CII); using a lot with a lower CII/CI resulted in a higher success rate. The odds of successful isolation was 8.67 times higher when a vial with CII/CI ratio <0.204 was used than when a vial with CII/CI ≥ 0.204 was used, suggesting that CII/CI ratio may be a strong predictor to distinguish potential lot success. This study provides a framework for improved enzymatic digestion in human islet isolation.

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“…42) is a practical and complete method for the assessment of cell conditions. Alternatively, the mitochondrial oxygen consumption rate (OCR) has been proposed as a dynamic indicator of cellular viability (43)(44)(45). The central hypothesis is that the OCR of cells is directly proportional to viable tissue volume and that its normalization to DNA content is a measure of fractional viability.…”

Section: Islet Viabilitymentioning

confidence: 99%

Prediction of Clinical Outcome in Islet Allotransplantation

Bertuzzi

Ricordi

2007

Diabetes Care

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Glucose Stimulation of Cytochrome C Reduction and Oxygen Consumption as Assessment of Human Islet Quality

Abstract: The detection of glucose-stimulated cytochrome c reduction and oxygen consumption may have utility as criteria for the assessment of human islet quality.

Cited by 44 publications

References 43 publications

The ADP/ATP Ratio: A Novel Predictive Assay for Quality Assessment of Isolated Pancreatic Islets

The ADP/ATP Ratio: A Novel Predictive Assay for Quality Assessment of Isolated Pancreatic Islets

Enhancing the Success of Human Islet Isolation Through Optimization and Characterization of Pancreas Dissociation Enzyme

Prediction of Clinical Outcome in Islet Allotransplantation

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