Related Experiment Videos
Cyclic ADP-ribose measurements in rat pancreatic islets
W J Malaisse1, Y Kanda, K Inageda
1Laboratory of Experimental Medicine, Brussels Free University, Belgium.
Biochemical and Biophysical Research Communications
|February 24, 1997
Summary
Cyclic ADP-ribose levels in rat pancreatic islets are low upon isolation but increase significantly with incubation. This suggests a potential role in islet cells, but not as a direct factor in glucose-stimulated insulin release.
Area of Science:
- Endocrinology
- Cell Biology
- Biochemistry
Background:
- Cyclic ADP-ribose (cADPR) is a signaling molecule with potential roles in calcium mobilization.
- Its presence and function in pancreatic islets, crucial for glucose homeostasis, remain incompletely understood.
Purpose of the Study:
- To quantify cyclic ADP-ribose levels in rat pancreatic islets.
- To investigate the influence of glucose and fructose on islet cADPR content.
- To compare islet cADPR levels with other tissues and cell types.
Main Methods:
- Radioimmunological assay was employed to measure cyclic ADP-ribose.
- Rat pancreatic islets were isolated and subjected to varying incubation conditions.
- cADPR content was measured immediately after isolation and after 90 minutes of incubation.
Main Results:
- Islet cyclic ADP-ribose content was significantly lower immediately after isolation (< or = 2.3 fmol/islet) compared to after 90 min incubation (26.4 fmol/islet).
- Incubation with D-glucose and/or D-fructose did not alter islet cADPR levels.
- When normalized to protein content, islet cADPR levels were 3- to 30-fold higher than in liver, whole pancreas, or tumoral islet cells.
Conclusions:
- The substantial increase in cyclic ADP-ribose during incubation suggests a potential physiological role within pancreatic islet cells.
- These findings do not support the hypothesis that cyclic ADP-ribose acts as a coupling factor in hexose-stimulated insulin release.