Deshaies Y, Géloën A, Paulin A, Marette A, Bukowiecki L J
Department of Physiology, School of Medicine, Laval University, Québec, Canada.
Horm Metab Res. 1993 Jan;25(1):13-6. doi: 10.1055/s-2007-1002036.
This study describes the consequences of sustained exposure to the nonspecific beta adrenergic agonist isoproterenol on the activity of lipoprotein lipase (LPL) in tissues that are sites for a large portion of the intravascular hydrolysis of triacylglycerols. Chronic exposure to isoproterenol was accomplished by means of osmotic pump infusion during four consecutive days, and assessment of the activity of LPL was performed at the end of the treatment. Four days of ISO infusion resulted in a large decrease in LPL activity of parametrial white adipose tissue, which declined to half of that found in the untreated group. In contrast, brown adipose tissue LPL activity was greatly increased (approximately threefold) by ISO treatment. The beta agonist raised LPL activity in red vastus lateralis muscle by a factor of four over control values, whereas heart enzyme activity was not significantly altered by the drug. These results demonstrate that catecholamines are part of the factors which determine the tissue specificity of LPL regulation. The tissue-specific changes in enzyme activity in response to isoproterenol, which are in very good agreement with the known metabolic actions of catecholamines in adipose and skeletal muscle tissues, attest to the key role of the enzyme in the partitioning of lipid substrates in situations of increased sympathetic activity.
本研究描述了持续暴露于非特异性β肾上腺素能激动剂异丙肾上腺素对脂蛋白脂肪酶（LPL）活性的影响，LPL参与大部分血管内甘油三酯水解，其作用位点涉及多个组织。通过渗透泵连续四天输注异丙肾上腺素以实现长期暴露，在治疗结束时评估LPL活性。四天的异丙肾上腺素输注导致子宫旁白色脂肪组织中LPL活性大幅下降，降至未治疗组的一半。相反，棕色脂肪组织中的LPL活性通过异丙肾上腺素治疗大幅增加（约三倍）。β激动剂使股外侧肌红色肌肉中的LPL活性比对照值提高了四倍，而心脏酶活性未因该药物而发生显著改变。这些结果表明，儿茶酚胺是决定LPL调节组织特异性的因素之一。对异丙肾上腺素的酶活性组织特异性变化与儿茶酚胺在脂肪和骨骼肌组织中的已知代谢作用非常一致，这证明了该酶在交感神经活动增加情况下脂质底物分配中的关键作用。
