Concentrations of elements in dying thymocytes from the thymus gland of diabetic rats.

Atrophy of the thymus gland occurs in rats made diabetic by a single injection of the drug streptozotocin. Histological studies show the presence of thymocytes with pyknotic nuclei in thymus tissue taken from diabetic animals. Analysis of the elemental content of the pyknotic cells was carried out on freeze dried frozen sections of thymus tissue using the technique of X-ray microanalysis. There was no loss of elements from cells which had undergone the early morphological changes characteristic of pyknosis and which showed the condensed chromatin of pyknotic nuclei. However as the cells shrank and lost the clear distinction between nucleus and cytoplasm there was a loss of elements, particularly Mg and K from the cells. The changes in distribution of elements in the dying thymocytes suggest a method of cell death which does not involve disruption of the plasma membrane.