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Updated: Oct 13, 2026
A Method for Mouse Pancreatic Islet Isolation and Intracellular cAMP Determination
Published on: June 25, 2014
'Classical' and 'new' diabetogens--comparison of their effects on isolated rat pancreatic islets in vitro
E Peschke1, H Ebelt, H J Brömme
1Institute of Anatomy and Cell Biology, Martin Luther University, Halle-Wittenberg, Saale, Germany.
Abstract:
This study compares functional and morphological alterations caused by application of alloxan, streptozotocin, xanthine oxidase/hypoxanthine (generation of reactive oxygen species), or S-nitroso-N-acetyl-D,L-penicillamine (SNAP, liberation of nitric oxide) to isolated rat pancreatic islets in vitro. In perifusion experiments, membrane leakage--detected by non-stimulated insulin release--was found after application of all drugs, but showed a substance-specific time pattern. Twenty-four hours after application of the classical diabetogens (alloxan or streptozotocin), potassium chloride- and glucose-stimulated insulin secretion were markedly reduced, while a persistent reduction was observed neither after exposure to xanthine oxidase/hypoxanthine, nor to SNAP. Morphological analysis of the islets revealed that nearly all beta-cells were destroyed following alloxan or streptozotocin treatment, while the majority of beta-cells were configured regularly after application of xanthine oxidase/hypoxanthine or SNAP. Necrotic cells found after xanthine oxidase/hypoxanthine usually differed in morphology from those observed after application of the classical diabetogens. While the former cells were characterised by swollen nuclei, the latter had shrunken nuclei with irregular condensed chromatin. Apoptosis was found only following nitric oxide exposure. Due to these differences, it seems unlikely that alloxan, streptozotocin, xanthine oxidase/hypoxanthine, and nitrix oxide have a common major feature in their toxic action.
Insights
Alloxan and streptozotocin cause significant beta-cell destruction and reduced insulin secretion in rat islets. Other agents like xanthine oxidase/hypoxanthine and SNAP induce different cellular changes, suggesting varied toxic mechanisms.
Area of Science:
- Endocrinology
- Cell Biology
- Toxicology
Background:
- Pancreatic beta-cells are crucial for insulin production.
- Understanding the mechanisms of beta-cell toxicity is vital for diabetes research.
- Alloxan and streptozotocin are common diabetogenic agents, but their precise actions differ from reactive oxygen species and nitric oxide donors.
Purpose of the Study:
- To compare the functional and morphological effects of alloxan, streptozotocin, xanthine oxidase/hypoxanthine, and S-nitroso-N-acetyl-D,L-penicillamine (SNAP) on isolated rat pancreatic islets.
- To elucidate the distinct toxic pathways of these agents in vitro.
Main Methods:
- Isolated rat pancreatic islets were exposed to alloxan, streptozotocin, xanthine oxidase/hypoxanthine, or SNAP.
- Perifusion experiments assessed membrane leakage and insulin secretion (basal, glucose-, and KCl-stimulated).
- Morphological analysis examined beta-cell integrity, cell death (necrosis, apoptosis), and nuclear characteristics.
Main Results:
- All agents caused membrane leakage, but with substance-specific timing.
- Alloxan and streptozotocin markedly reduced insulin secretion and destroyed beta-cells with shrunken nuclei.
- Xanthine oxidase/hypoxanthine and SNAP showed less impact on insulin secretion and preserved beta-cell morphology, with distinct necrotic cell features (swollen nuclei) and apoptosis observed only after SNAP exposure.
Conclusions:
- Alloxan and streptozotocin induce beta-cell death via distinct mechanisms compared to xanthine oxidase/hypoxanthine and SNAP.
- Reactive oxygen species and nitric oxide exhibit different cytotoxic profiles, suggesting varied pathways of pancreatic islet damage.
- The toxic actions of these diabetogenic agents are not uniform, highlighting the complexity of beta-cell dysfunction.
