Effects of thyroid hormone on the chemical constituents of different tissues of the chequered water-snake, Natrix piscator

Abstract l -Thyroxine maintains the body and liver weights of thyroidectomized snakes at the levels found in intact animals but has no effect on kidney weight. The decreases in the levels of muscle glycogen, plasma cholesterol (total, esterified and free), liver esterified fatty acids and cholesterol (esterified), and adipose tissue triglycerides (TG), and the increase in the levels of liver FFA and cholesterol (free) following thyroidectomy are brought up to intact levels by l -thyroxine. However, the concentration of plasma protein, FFA, esterified fatty acids and TG in the plasma and liver, which decreases, and of FFA in the adipose tissue and glycogen in liver, which increases, following thyroidectomy, are increased and decreased, respectively, when compared to intact snakes following the administration of l -thyroxine into thyroidectomized snakes. Plasma glucose level, on the other hand was not affected by thyroidectomy but was elevated by l -thyroxine.