Studies on the pathology of experimental zinc deficiency in guinea-pigs.

Zinc deficiency was produced in guinea-pigs by feeding a diet containing 1.25 micrograms Zn per g of diet over a period of 60 days. A significant reduction in serum and tissue (kidney, liver and testis) Zn concentration was observed in the Zn-deficient (ZnD) group. Gross lesions were thickening of skin, atrophy of testis and thyroid and enlargement of adrenals. Histologically, there was parakeratosis, hyperkeratosis and acanthosis in skin, tongue and oesophagus, degeneration and strophy of testis, necrosis of the pancreas, atrophy of the thyroid, atrophy of the zona glomerulosa and hyperplasia of the zona reticularis and medulla of the adrenals. In order to study the response to Zn supplementation, the Zn-replete diet was fed over a period of 15 days to guinea-pigs which had been given the ZnD diet for 45 days. These animals exhibited marked, though not complete, improvement in the pathological changes.