Regeneration of the islets of Langerhans in the guinea pig

Summary The regeneration of the islets of Langerhans in the guinea pig was studied after intravenous injection of alloxan. A number of cells in the islets was destroyed within 24 h after alloxan, but after 48 h there was a rapid proliferation of the surviving cells of the islets. This depended on the dosage of the drug as well as the timing. Electron microscopy of the islet at 48 h showed that the dividing cells had small electron dense granules and resembled a subtype of normal A cells, whose function is not yet known. There were also many agranular cells in the islet. These two groups of cells seen in the regenerating islet could be precursor cells, which could differentiate into cells. There was no evidence for transformation of duct cells or acinar cells into islet cells. None of the guinea pigs became permanently diabetic. This was probably due to inadequate dosage which resulted in only partial degeneration of the cells followed by regeneration and recovery. There was also some regeneration of the liver, kidney and the adrenal cortex following alloxan.The author is grateful to Professor R. Barer for his guidance and for providing the facilities for this study. Thanks are also due to Mrs. D. Barraclough for technical assistance and to Mrs. M. Hollingsworth for assistance with the photographsThis work was financed by a grant from the Cystic Fibrosis Research Trust