Repair of the anemia and hyperlipidemia of the hypothyroid dog.

Abstract

Sixteen dogs were made hypothyroid with radioiodine. The hypothyroidism was characterized by a decreased metabolic rate, decreased protein-bound iodine and total thyroxine, and increased serum cholesterol, total lipid and phospholipid. The metabolic rate was restored to normal or supranormal levels with both l-thyroxine and dinitrophenol. The anemia was of the normocytic normochromic variety, with a decreased rate of red cell formation. The total red cell volume returned to normal with l-thyroxine, but was unaffected by DNP, iron, copper, cobalt, pyridoxine, folic acid and vitamin B12 therapy. This study shows that in the hypothyroid dog there can be a dissociation between metabolic rate and erythropoiesis, and that thyroxine may act by some pathway other than by increasing O2 consumption. Thyroxine administration raised the PBI concentration and the free thyroxine level, but these were not changed by DNP therapy. Both l-thyroxine and DNP administration restored the serum cholesterol levels to normal. (En...