title: Palmitic acid metabolism in the soleus muscle in vitro in hypo- and hyperthyroid rats.
abstract: The aim of this study was to establish whether the rate of fatty acid (FA) incorporation and its utilization by the isolated soleus muscle is modified under conditions of thyroid hormone deficit or excess. The rate of palmitic acid (PA) uptake, oxidation and incorporation into intramuscular lipids with increasing PA concentration (0.5-1.5 mM) in the incubation medium were determined. In hypothyroid rats intramuscular triacylglycerol (TG) synthesis was increased, while the rate of PA oxidation to CO2 and incorporation into mono- and diacylglycerols (MG/DG) and phospholipids (PL) remained unchanged. In rats with triiodothyronine (T3) excess the rate of all processes studied was enhanced, although the percentage incorporation of PA into different classes of intramuscular lipids was fairly constant and, independently of thyroid state and FA concentration in the medium, was 56-66% for TG, 9-14% for MG/DG and 24-32% for PL. Our results thus indicate that even short-term T3 excess accelerates the rate of FA uptake and metabolism in the oxidative soleus muscle, whereas in hypothyroid rats only intramuscular TG synthesis is affected.
authors.affiliation: Department of Applied Physiology, Medical Research Centre, Polish Academy of Sciences, 5 Pawińskiego St., 02-106, Warsaw, Poland.
authors.forename: Monika
authors.initials: M
authors.lastname: Górecka
authors.forename: Marcin
authors.initials: M
authors.lastname: Synak
authors.forename: Józef
authors.initials: J
authors.lastname: Langfort
authors.forename: Hanna
authors.initials: H
authors.lastname: Kaciuba-Uściłko
authors.forename: Ewa
authors.initials: E
authors.lastname: Zernicka
mesh_terms: D000818:Animals; D002245:Carbon Dioxide / Q000378:metabolism; D006980:Hyperthyroidism / Q000378:metabolism*; D007037:Hypothyroidism / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism*; D010084:Oxidation-Reduction; D019308:Palmitic Acid / Q000493:pharmacokinetics*; D010743:Phospholipids / Q000097:blood; D051381:Rats; D017208:Rats, Wistar; D014280:Triglycerides / Q000097:blood
chemical_list: D010743:Phospholipids; D014280:Triglycerides; D002245:Carbon Dioxide; D019308:Palmitic Acid