The zinc distribution was determined in adult rats 15 d after the begi
nning of thyroxin (T4) treatment. The zinc was investigated in RBC, pl
asma, brain, heart, muscle, liver, kidney, spleen, thymus, and bone. T
he results confirm that T4 modified zinc in RBC and tissues. Zinc was
significantly decreased in RBC (45%) but no significant difference was
found in plasma zinc between experimental and control groups. Zinc wa
s decreased 33% in muscle and 14% in liver, but was increased 10% in k
idney. Brain, heart, spleen, thymus were the least affected tissues. B
one zinc was decreased but no statistically significant difference was
found between the two groups.