Comparative Effects of Long-Acting Thyroid Stimulator and Pituitary Thyrotropin on the Intermediate Metabolism of Thyroid Tissue<i>in Vitro</i>

Abstract

Long-acting thyroid stimulator (LATS) increases the uptake and oxidation of glucose and enhances the formation of lactate by sheep thyroid slices in a manner analogous to the action of pituitary thyrotropin (TSH). LATS also increases phospholipogenesis (indicated by 32P incorporation), but the specificity of individual phospholipid response may be different from that with TSH. LATS stimulates the incorporation of 32P orthophosphate into lecithin and monophosphatidylinositol to about the same degree, whereas TSH action is directed mainly toward the latter phospholipid. In contrast to TSH, LATS consistently increases the labeling of neutral lipids from U-14C glucose, although their effects on decreasing the ratio of radioactive triglyceride/diglyceride are similar. (Endocrinology79: 949, 1966)