Morphological changes of isolated rat pancreatic islets: a structural, ultrastructural and morphometric study
- 1 September 2006
- journal article
- Published by Wiley in Journal of Anatomy
- Vol. 209 (3), 381-392
- https://doi.org/10.1111/j.1469-7580.2006.00620.x
Abstract
Improved techniques for pancreatic islet extraction can yield a reasonable number of transplantable cells. However, the isolation and purification process may damage the islets and impair their physiological functions. The aim of this study was to determine the effect of the isolation procedure on the structure of isolated islets and to correlate this with their functionality. Islets were isolated from rat pancreata and purified by Eurocollins-Ficoll discontinuous density gradient processing, and then processed for light microscopy, and scanning and transmission electron microscopy. Morphometric analysis was also performed. Islet functionality was determined by reversal of streptozotocin-induced diabetes and the intraperitoneal glucose tolerance test in a syngeneic rat model of pancreatic islet transplantation. Fragments of variable size and shape comprised a relatively large proportion (26%) of the isolated endocrine tissue. Isolated islets showed slight alterations of cell ultrastructure. Major damage (including breakage of the plasma membrane) and loss of cells were observed in the peripheral cells of the isolated islets. An equal mass of islet equivalent (IEq, islets with an average diameter of 150 microm), but with a different islet equivalent/islet number ratio, was transplanted in diabetic animals. When larger and more complete islets were transplanted (higher ratio), better function of the graft was observed by reversal of hyperglycaemia and response to the glucose tolerance test as compared with the functionality and response of smaller (fragmented) islets transplanted (lower ratio). Digestion, trauma and hypoxia during isolation are responsible for qualitative and quantitative changes of isolated islets. Alterations in normal secretory function after the transplant were related to lower islet equivalent/islet number ratio. The incomplete integrity of the islets may explain the failure of the fine glycaemic metabolic regulation.Keywords
This publication has 42 references indexed in Scilit:
- Isolated pancreatic islets of the rat: An immunohistochemical and morphometric studyThe Anatomical Record, 1993
- Morphologic basis for loss of regulated insulin secretion by isolated rat pancreatic isletsThe Anatomical Record, 1993
- Isolated Pancreatic Islets of the Rat: An Ultrastructural StudyCells Tissues Organs, 1992
- Morphometry and Function of Islet Cells after Different Forms of Drainage at Pancreatic Transplantation in RatsEuropean Surgical Research, 1990
- STUDIES OF THE ISOLATION AND VIABILITY OF HUMAN ISLETS OF LANGERHANS1,2Transplantation, 1988
- Natural history of intrahepatic canine islet cell autografts.JCI Insight, 1986
- MORPHOLOGICAL CHANGES IN PANCREATIC FRAGMENTS PREPARED FOR TRANSPLANTATION BY COLLAGENASE TREATMENTTransplantation, 1984
- Evidence against the presence of tight junctions in normal endocrine pancreasDiabetes, 1984
- Functional differences between rat islets of ventral and dorsal pancreatic origin.JCI Insight, 1982
- Increase of gap junctions between pancreatic B-cells during stimulation of insulin secretion.The Journal of cell biology, 1979