The Action of p-Synephrine on Lipid Metabolism in the Perfused Rat Liver

作     者：Juliany Fontoura da Silva-Pereira Andrea Luiza de Oliveira Valoto Livia Bracht Geferson de Almeida Goncalves Rosane Marina Peralta Adelar Bracht 

作者机构：Department of BiochemistryUniversity of MaringaMaringaBrazil Faculdade IntegradoCampo MouraoBrazil 

出 版 物：《Journal of Biosciences and Medicines》 (生物科学与医学（英文）)

年 卷 期：2017年第5卷第5期

页      面：8-21页

学科分类：1002[医学-临床医学] 100201[医学-内科学(含：心血管病、血液病、呼吸系病、消化系病、内分泌与代谢病、肾病、风湿病、传染病)] 10[医学] 

基　　金：Conselho Nacional de Desenvo- lvimento Cientifico e Tecnologico (CNPq) 

主　　题：Hepatic Lipid Metabolism Lipolysis Fatty Acid Release Fatty Acid Oxidation 

摘      要：p-synephrine and p-octopamine were found to increase lipolysis in adipocytes. The present study approaches the question if these compounds, natural products of the bitter orange (Citrus aurantium fruit), increase lipolysis and fatty acid oxidation in the liver. Experiments were done in the perfused rat liver. Non-recirculating hemoglobin-free perfusion was done using the Krebs/ Henseleit-bicarbonate buffer (pH 7.4) as perfusion fluid. Both p-synephrine and p-octopamine, at the concentrations of 100 μM, were found to stimulate the hepatic triacylglycerol lipase by 40% and 51%, respectively. These seem to be the maximal stimulations possible in the liver. In the perfused liver, p-synephrine, when present at an initial concentration of 500 μM, was able to increase the non-esterified fatty acid release after one hour of recirculating perfusion. The effects of p-synephrine on the oxidation of exogenously supplied [1-14C]octanoate and [1-14C]oleate were minimal. Only oxygen uptake, already stimulated by octanoate or oleate, was additionally increased by the infusion of p-synephrine. These results contrast with those obtained in a previous study with p-octopamine, which increased the production of 14CO2 from both [1-14C]octanoate and [1-14C]oleate. Apparently only the oxidation of endogenous fatty acids is stimulated by p-synephrine. On the other hand, both p-synephrine and p-octopamine stimulate the hepatic triacylglycerol lipase to a much lesser extent than the adipocyte lipase. It can be concluded that p-synephrine affects much more carbohydrate metabolism in the liver than lipid metabolism.