title: Inhibition of lipolysis and cyclic AMP accumulation in white fat cells by tetracycline.
abstract: The effects of tetracycline on the metabolism of isolated rat white fat cells were examined. Tetracycline at a concentration of 0.05 mg/ml inhibited lipolysis due to 0.075 or 0.15 muM norepinephrine, but not that due to adenosine deaminase, theophylline, dibutyryl cyclic AMP or 1.5 muM norepinephrine. Higher concentrations of tetracycline (1 mg/ml) inhibited lipolysis due to all added agents except dibutyryl cyclic AMP. The accumulation of cyclic AMP after 5 minutes incubation with 0.15 muM norepinephrine plus adenosine deaminase was inhibited by 0.05 mg/ml of tetracycline. The large rise in cyclic AMP accumulation at 5 minutes due to 1.5 muM norepinephrine in the presence of 100 muM theophylline was only slightly inhibited by 0.05 or 0.1 mg/ml of tetracycline. Tetracycline at 1 mg/ml did markedly inhibit cyclic AMP accumulation due to all added agents. The stimulation of adenylate cyclase activity of fat cell ghosts by norepinephrine or fluoride was inhibited by 0.05 mg/ml or greater concentration of tetracycline. Insulin-stimulated glucose oxidation by fat cells was inhibited by 1 mg/ml of tetracycline. These results suggest that the anti-lipolytic action of tetracycline on rat fat cells is secondary to inhibition of cyclic AMP accumulation.
mesh_terms: D000067956:Adenylyl Cyclase Inhibitors; D000273:Adipose Tissue / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism*; D003864:Depression, Chemical; D005260:Female; D005990:Glycerol / Q000378:metabolism; D066298:In Vitro Techniques; D050356:Lipid Metabolism; D009638:Norepinephrine / Q000494:pharmacology; D051381:Rats; D013752:Tetracycline / Q000494:pharmacology*; D013806:Theophylline / Q000494:pharmacology
chemical_list: D000067956:Adenylyl Cyclase Inhibitors; D003994:Bucladesine; D013806:Theophylline; D000242:Cyclic AMP; D013752:Tetracycline; D005990:Glycerol; D009638:Norepinephrine