Effect of lithium chloride on the thyroid gland in albino rats

The character of morphological and functional changes in the thyroid tissue of albino rats was studied by radiometric, histological, and biochemical methods during administration of lithium chloride to the animals for three weeks in doses of 0.5 meq/kg (Group 1), and 1 meq/kg (Group 2) daily. The inhibitory action of lithium chloride on hormone production in the thyroid gland and on the secretion of thyroid hormones into the blood stream was shown to be directly dependent on the dose of the compound and the lithium concentration in the blood. The results of intravital radiometry and morphological analysis of the organs of the animals of group 1 showed some activation of the gland, but secretion of hormones into the blood stream was inhibited. An increase in the lithium concentration inhibited hormone production and the secretion of thyroid hormones into the blood stream.