Circulating thymic hormone levels in zinc deficiency

The effect of zinc deficiency (Zn − ) on the circulating thymic hormone (FTS) levels in A/J mice was studied. After 3 weeks of feeding the mice a Zn − diet, FTS levels were markedly reduced and after 17 weeks, FTS was undetectable. By contrast, the zinc-supplemented (Zn + ) group seemed to maintain FTS levels better than the normal diet group with aging. On the other hand, spleen spontaneous rosette-forming cells (sRFC) were studied for their azathioprine (AZ) sensitivity in A/J mice on different diets. The Zn − mice had fewer sRFC than did the normally fed or Zn + mice. The role of zinc in controlling levels of FTS and thus thymic function is discussed.