Heavy metals and the mammalian thymus: in vivo and in vitro investigations.

This experiment was performed to investigate changes in the thymus of Wistar-strain male rats administered cadmium chloride (CdCl2), mercuric chloride (HgCl2), and lead chloride (PbCl2) salts. The study involved measurement of: 1) deoxyribonucleic acid (DNA) content; 2) ascorbic acid (vitamin C) content; 3) incorporation of 3h-thymidine during in-vitro investigation; and 4) histological and morphological changes. It was shown in investigations on DNA content that administration of heavy metal salts caused an average 76% decrease in DNA content compared to the control. Moreover, in the thymus of experimental animals, an average 69% decrease in vitamin C content was recorded. In in vitro cultures, heavy metal salts decreased the incorporation of 3H-thymidine in thymic cells.