CONTROL OF LIVER REGENERATION AND NUCLEIC ACID CONTENT BY THE THYROID, WITH OBSERVATIONS ON THE EFFECTS OF PYRIMIDINES

Abstract

Observations have been made concerning the influence of the thyroid, and of pyrimidine and thiopyrimidine admn., upon rat liver regeneration and nucleic acid and N content. The evidence shows that the thyroid is a regulator of liver regeneration, as well as of liver nucleic acid and protein mobilization. In animals over 4 months old, but not in younger animals, the control over regeneration can, in the absence of the thyroid, be taken over by something else. Ingested pyrimidines have no effect on liver regeneration, or on nucleic acid and N content. Ingested thiopyrimidines, in high concns., reduce the regenerative capacity of the liver; and this effect is not due to inhibition of the formation of thyroid hormone. A postulated inhibition of pyrimidines by thiopyrimidines was neither proved nor ruled out.