[Large-scale isolation of islets of Langerhans in dogs and human]

Transplantation of isolated islets of Langerhans is a perspective method of treating type 1 diabetes. The first prerequisite for its implementation is to obtain sufficient amounts of vital islets. The objective to the authors' experiments was to introduce a method of massive isolation of islets of Langerhans from dogs which would serve as a model pro obtaining islets of Langerhans from humans and would permit to use them in future in clinical practice.

After excision of the dog pancreas the authors injected into the ducts a 1% collagenase solution and the tissue was deposited in a specially developed semi-automatic isolation system which consisted of a vibrating isolation chamber in which an isolation solution with controlled temperature circulated. As soon as the islets started to be released, the system was cooled and the disintegrated tissue was collected. The islets were separated from the acinar mass by centrifuging in a ficoll mass gradient. The islet function was tested by transplantation to athymic diabetic mice. A total of 15 isolations of dog islets was performed, incl. 5 which were evaluated quantitatively. In a similar way twice isolation from a human cadaverous pancreas was implemented. On average 6336 +/- 745 (+/-SD) purified dog islets were obtained. Their function was tested by normalization of the blood sugar after transplantation to diabetic mice. The authors obtained also vital highly purified human islets.

The authors developed a method of isolation of dog and human islets of Langerhans which makes it possible to obtain sufficient amounts of vital islet tissue which could be used for transplantation. A further task will be to standardize the process and adjust it to hygienic norms essential for clinical use.