Lipolysis in isolated epididymal adipocytes from genetically obese Zucker rat treated with 3,5,3'-L-triiodothyronine.

Abstract. Glycerol released by isolated epididymal adipocytes was measured in 6-8 weeks old genetically obese (fa/fa) and lean (C.c.a/-) male Zucker rats, ip treated or not treated with T3 (0.46, 2.3 and 4.6 nmol/100 g in a single injection or 4.6 nmol · (100 g)−1 · day−1 for 5 days). In the non-treated rats, lipolysis was less stimulated by adrenalin or isoproterenol in obese than in lean rats, whereas it was stimulated by theophylline up to the same level in both kinds of rats. A single injection of the T3 (highest dose) increased isoproterenol-induced lipolysis in the lean but not in the obese rats. The 5-day T3 treatment caused a stimulation of the adrenalin- or isoproterenol-induced li…