caa a22 4500 47577146X CHVBK 20180406123618.0 cr unu---uuuuu 170329e20000701xx s 000 0 eng 10.1007/s001250051463 doi (NATIONALLICENCE)springer-10.1007/s001250051463 Abnormal insulin and β-adrenergic modulation of lipoprotein lipase during refeeding after prolonged fasting in the Zucker rat [Elektronische Daten] [F. Picard, D. Richard, E. Timofeeva, Y. Deshaies] Aims/hypothesis. To characterise the response of tissue lipoprotein lipase to refeeding after prolonged (24 h) fasting in lean and obese Zucker rats, and to verify whether lipoprotein lipase in obese rats is resistant to the short-term action of insulin and escapes modulation by the β-adrenergic pathway.¶Methods. Lean Fa/? and obese fa/fa male Zucker rats fasted for 24 h and refed at will. Lipoprotein lipase activity in adipose and muscle tissues was assessed in the freely fed and fasted states and at various times during refeeding, with or without β-adrenergic blockade (propranolol).¶Results. The 24-h fast erased the phenotype-related differences in insulinaemia and adipose lipoprotein lipase activity present in freely fed rats. Adipose lipoprotein lipase increased twofold in obese rats 1 h after refeeding, whereas no change occurred at that time in lean rats. Activity remained at that level for at least 6 h after refeeding in obese rats, whereas in lean animals it was increased fivefold after 6 h of refeeding. In muscle of obese rats, lipoprotein lipase decreased in response to refeeding, but paradoxically increased twofold in lean animals. Giving propranolol to lean rats before refeeding abolished the atypical response of muscle lipoprotein lipase to food intake and restored the early (1 h after refeeding) increase in adipose lipoprotein lipase but had no effect in obese rats.¶Conclusion/interpretation. Refeeding after prolonged fasting activates the β-adrenergic pathway in lean rats, which transiently counteracts insulin-mediated modulation of lipoprotein lipase. The β-adrenergic pathway is not activated by refeeding in adipose tissue and muscle of the obese Zucker rat. In the obese Zucker rat, the early modulation of adipose lipoprotein lipase activity is abnormal upon refeeding after prolonged fasting, suggesting short-term resistance to the action of insulin. [Diabetologia (2000) 43: 866-874] Springer-Verlag Berlin Heidelberg, 2000 Keywords Lipoprotein lipase, obesity, Zucker rat, food deprivation, food intake, insulin, insulin resistance, β-adrenergic pathway, adipose tissue, skeletal muscle nationallicence Picard F. Center for Research on Energy Metabolism and Department of Anatomy and Physiology, School of Medicine, Laval University, Québec, Canada, CA aut Richard D. Center for Research on Energy Metabolism and Department of Anatomy and Physiology, School of Medicine, Laval University, Québec, Canada, CA aut Timofeeva E. Center for Research on Energy Metabolism and Department of Anatomy and Physiology, School of Medicine, Laval University, Québec, Canada, CA aut Deshaies Y. Center for Research on Energy Metabolism and Department of Anatomy and Physiology, School of Medicine, Laval University, Québec, Canada, CA aut https://doi.org/10.1007/s001250051463 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s001250051463 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Picard F. Center for Research on Energy Metabolism and Department of Anatomy and Physiology, School of Medicine, Laval University, Québec, Canada, CA aut NATIONALLICENCE 700 1- Richard D. Center for Research on Energy Metabolism and Department of Anatomy and Physiology, School of Medicine, Laval University, Québec, Canada, CA aut NATIONALLICENCE 700 1- Timofeeva E. Center for Research on Energy Metabolism and Department of Anatomy and Physiology, School of Medicine, Laval University, Québec, Canada, CA aut NATIONALLICENCE 700 1- Deshaies Y. Center for Research on Energy Metabolism and Department of Anatomy and Physiology, School of Medicine, Laval University, Québec, Canada, CA aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer