title: Effects of chronic treatments upon the brown adipose tissue of rats. II. Comparison between the effects of catecholamine injections and cold adaptation.
abstract: The role of noradrenaline in the trophic response of brown adipose tissue (BAT) to chronic and cold exposure was studied in young adult rats treated chronically with catecholamines. 2 In young rats, it was difficult to induce a BAT development with this type of treatment. After injection of a beta-agonist (isopropylnoradrenaline) directly upon BAT, a slight hypertrophy of the tissue was observed accompanied by a decrease of its relative protein content. 3 In adult rats, catecholamines were able to induce a growth of BAT and increases of the DNA and protein contents which were as great as in the BAT of cold-exposed rats. 4 Catecholamine treatments did not reproduce the effects of cold exposure on the phospholipids of BAT in either young or adult rats. 5 In the BAT of rats receiving chronically thyroxine and catecholamines, no synergy was observed. Moreover, a chronic treatment by thyroxine induced a slight increase of the DNA content of BAT in rats bred at room temperature, but prevented the marked DNA increase observed in cold-exposed animals.
mesh_terms: D000222:Adaptation, Physiological; D002001:Adipose Tissue, Brown / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D000367:Age Factors; D000818:Animals; D002395:Catecholamines / Q000494:pharmacology*; D003080:Cold Temperature; D004247:DNA / Q000378:metabolism; D006984:Hypertrophy / Q000209:etiology; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology; D010743:Phospholipids / Q000378:metabolism; D051381:Rats; D013974:Thyroxine / Q000009:adverse effects
chemical_list: D002395:Catecholamines; D010743:Phospholipids; D004247:DNA; D007545:Isoproterenol; D013974:Thyroxine; D009638:Norepinephrine