Thyroid hormones and cathepsin D activity in the rat liver, kidney and brain

The effect of thyroidectomy and subsequent treatment with tri-iodothyronine (T3), as well as that of thyrotoxicosis, was examined on cathepsin D activity in the rat liver, kidney and brain. Thyrotoxicosis resulted in a generalized increase in the enzyme activity in the 3 tissues; the effect of other thyroidal states was diverse and tissue-specific.