Investigations on isolated islets of Langerhans in vitro. Influence of temperature changes during preparation on some parameters of insulin metabolism.

Pancreatic islets of Wistar rats were prepared by digestion with collagenase and then washed and isolated at three different temperatures (4, 22 and 37 degrees C). The efficiency of washing with regard to proteolytic and collagenolytic activities in the wash buffer was not affected by the temperatures used. The islet thiol:protein-disulphide oxidoreductase activity (EC 1.8.4.2) was apparently unchanged, whereas washing temperatures lower than 37 degrees C resulted in a diminished insulin content. The insulin secretion of islets, isolated at 4 degrees C, is reduced in response to glucose without changing the sigmoidal shape of dose-response curve.