HISTOLOGICAL CHANGES IN RATS RENDERED HYPERGLYCÆMIC BY INJECTION OF DEHYDROASCORBIC ACID

¹ The Departments of Pathology and Clinical Chemistry, University of Edinburgh

1. Rats made hyperglycæmic by repeated intravenous injections of dehydroascorbic acid (DHA) were killed 24 hrs. (Group 1) and four days (Group 2) after the last DHA injection, and the pancreas, kidneys, liver, adrenals and thyroid were examined histologically.

2. The most marked lesions were found in the islets of Langerhans of the pancreas. In Group 1 animals there was degranulation and shrinkage of the -cells, pyknosis of their nuclei, and occasionally vacuolation of their cytoplasm; rarely, actual disintegration of cells was observed. No glycogen was stainable in the -cells. In Group 2 rats the islets were small: the -cells were reduced in numbers, shrunken and usually agranular, with pyknotic nuclei. Cytoplasmic vacuolation was obvious, and though some glycogen was demonstrable in the cells, all the vacuolation could not be accounted for in this way.

3. The kidneys showed no significant degenerative change in either group, but there was some glycogen storage in the tubular cells of Group 2 rats.

4. In the adrenal cortices, a reduction of Sudanophil and Feulgenpositive material was observed in the zona glomerulosa and the zona fasciculata in the males of both groups, while no such change could be demonstrated in the females of Group 2.

5. No change of note was found in the livers or thyroids of the experimental animals.

6. The main lesions occurring as a result of injection of IDHA, those in the islets of Langerhans, are thus very similar to the lesions of experimental alloxan diabetes, but it appears that for comparable islet damage, DHA produces higher blood sugar concentrations.

Note:

One of us (S. K. B.) wishes to thank the University of Edinburgh for the grant of a Post-Graduate Fellowship which made possible his participation in this work.