AJP - Endocrinology and Metabolism, Vol 240, Issue 1 18-E23, Copyright © 1981 by American Physiological Society
Protein synthesis in perfused rat liver following thyroidectomy and hormone treatment
D. E. Peavy, J. M. Taylor and L. S. Jefferson
Rat livers perfused in situ were used to investigate the effects of thyroid
hormone deficiency and subsequent hormone replacement on hepatic protein
synthesis and secretion. Following surgical thyroidectomy, production of
albumin and total secretory proteins was reduced by 50%, whereas the
synthesis of retained intracellular proteins was reduced by only 20%
compared to the respective control rates. The 28% reduction in the
synthesis of total liver proteins (secreted plus retained) was associated
with a fall of similar magnitude in the tissue RNA level. Treatment of
thyroidectomized rats with various doses of thyroid hormones indicated a
regimen that restored the rate of synthesis of total liver proteins and the
concentration of RNA to normal levels. This treatment regimen increased the
synthesis of retained proteins to 115% of the control rate, but produced
only modest increases in the production of albumin and total secretory
proteins. These findings indicated an impairment in protein secretion in
livers of thyroidectomized rats that persisted after the defect in protein
synthesis was corrected by thyroid hormone treatment.
