Influence of thyroid hormone on the phospholipid composition of lung tissue and surfactant of rats.

Thyroid hormone is an important regulator of lipid metabolism in vivo. The effect of thyroid hormone on the phospholipid composition of lung tissue and surfactant has been studied in hypothyroid and hyperthyroid rats in comparison with the control rats. Rats were made hyperthyroid by administering 1 mg of L-thyroxine/kg body weight for six days. Another group of rats was rendered hypothyroid by injecting 1 mci of Na I131 to each rat. Phosphatidyl choline, lysophosphatidyl choline, lysophosphatidyl ethanolamine, phosphatidyl ethanolamine, and sphingomyclin, were estimated by thin layer chromatography. A decrease in phospholipids in hypothyroid and an increase in the hyperthyroid rats was observed. This can be attributed to the altered thyroid activity.