Abstract
Activities of NADPH-cytochrome c reductase, NADPH-dichlorophenolindophenol diaphorase and glucose-6-phosphate dehydrogenase in the anterior pituitary and in the liver were compared in normal and in thyroidectomized rats, with or without thyroxine (T4) supplement. Responses of pituitary enzymes to thyroidectomy and T4 supplement were different from, in some cases even opposite to, those of the same liver enzymes. The typical response was observed in glucose-6-phosphate dehydrogenase; the enzyme activity in the pituitary increased by thyroidectomy and the increased activity was suppressed by T4 supplement, whereas the activity in the liver decreased by thyroidectomy and increased by T4 treatment. The mechanisms and the physiological significance of these findings were discussed in connection with protein synthesis in the two tissues.
