The mechanism of thyrotrophin action in relation to lipid metabolism in thyroid tissue.
1. The effects of thyrotrophin in vitro on the incorporation of [(14)C]-glucose, -glycerol, -palmitate and -oleate into the lipids of thyroid tissue were examined. 2. Thyrotrophin increased the incorporation of these (14)C-labelled precursors into phosphatidylinositol specifically. 3. Thyrotrophin also increased the proportion of (14)C radioactivity from labelled glucose, glycerol, palmitate and oleate incorporated into the 1,2-diglycerides. 4. The addition of thyrotrophin to thyroid slices for 10min., after 2hr. of prelabelling with [(14)C]glycerol, also increased the proportion of (14)C radioactivity incorporated into the 1,2-diglyceride fraction. 5. After incubation of thyroid tissue with [1-(14)C]palmitate, thyrotrophin caused a two- to three-fold increase in the specific radioactivity of palmitate isolated from phosphatidylinositol and 1,2-diglycerides. In contrast, the specific radioactivity of palmitate isolated from the choline and ethanolamine phosphoglycerides, 1,3-diglycerides and triglycerides was not increased by thyrotrophin.
D000818:Animals; D002247:Carbon Isotopes; D004285:Dogs; D005947:Glucose / Q000378:metabolism; D005989:Glycerides / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism; D066298:In Vitro Techniques; D050356:Lipid Metabolism; D009829:Oleic Acids / Q000378:metabolism; D010169:Palmitic Acids / Q000378:metabolism; D010716:Phosphatidylinositols / Q000378:metabolism; D012756:Sheep; D013961:Thyroid Gland / Q000187:drug effects* / Q000378:metabolism; D013972:Thyrotropin / Q000494:pharmacology*
D002247:Carbon Isotopes; D005989:Glycerides; D009829:Oleic Acids; D010169:Palmitic Acids; D010716:Phosphatidylinositols; D013972:Thyrotropin; D005947:Glucose; D005990:Glycerol