ABSTRACT
BACKGROUND & AIMS: The liver is the main organ regulating metabolism. In spite of that, few studies examine liver metabolism in cachexia, a wasting syndrome associated with increased morbidity and mortality in cancer. Cachexia induces major metabolic disruption, inflammation and fat and lean mass loss. We have previously shown impairment of hepatic lipid metabolism in cancer cachexia that contributes to the aggravation of the symptoms. The present study addresses the effects of Conjugated Linoleic Acid supplementation upon liver lipid metabolism in cachectic rats. METHODS: Male Wistar rats were randomly assigned to control groups (C) receiving 0.9 NaCl (Placebo CP); or to groups supplemented with sunflower oil (CSF), supplemented with CLA (CCLA), or still, to tumour bearing animals (T) receiving NaCl (TP), sunflower oil (TSF), or CLA (TCLA). Supplementation (0.5 ml) by gavage was carried out for 14 days. Body weight, dietary intake, glucose, cholesterol and triacylglycerol plasma content, liver glycogen and triacylglycerol content and mRNA expression of liver carnitine palmitoyltransferase I and II (CPT I and II), as well as microsomal triglyceride transfer protein (MTP), liver fatty acid-binding protein (L-FABP), peroxisome proliferator-activated receptor-alpha (PPAR-alpha), and apolipoprotein B (apoB), were assessed. RESULTS: Liver CPT II activity was reduced in all groups, when compared with CP. Hepatic mRNA expression of MTP, apoB and FABP was reduced in TCLA, when compared with all groups. TCLA also presented increased hepatic and plasma triacylglycerol content, when compared with all T groups. Adipose tissue-derived inflammatory factors were assessed. No differences among the groups were observed in regard to Retro Peritoneal Adipose Tissue cytokine (IL-1ß, IL-6, and TNF-α) protein content and expression, with the exception of IL-10 in tumour-bearing animals. In the Epididymal Adipose Tissue, the inflammatory cytokines were augmented in TCLA, compared with all other groups. CONCLUSION: CLA supplementation fails to promote the re-establishment of hepatic lipid metabolism in tumour-bearing animals, and therefore is not recommended in cancer-related cachexia.
Subject(s)
Cachexia , Linoleic Acids, Conjugated , Lipid Metabolism/drug effects , Liver , Neoplasms/complications , Adipose Tissue/chemistry , Adipose Tissue/metabolism , Animals , Cachexia/etiology , Cachexia/metabolism , Dietary Supplements , Inflammation/chemically induced , Inflammation/metabolism , Linoleic Acids, Conjugated/adverse effects , Linoleic Acids, Conjugated/pharmacology , Lipids/analysis , Liver/chemistry , Liver/drug effects , Liver/metabolism , Male , Rats , Rats, WistarABSTRACT
BACKGROUND & AIMS: Cancer cachexia affects intermediary metabolism with intense and general catabolism. Walker 256 tumor is a model injected either subcutaneously (Sc) or intraperitoneally (Ip), with different metabolic features. Beta-hydroxy beta-methylbutyrate (HMbeta) is a leucine metabolite with anti-catabolic properties, the aim of this study being to investigate its effects on metabolic parameters in both tumor models. METHODS: Controls (subcutaneous control group (ScC) and intraperitoneal control group (IpC)) and supplemented animals (subcutaneous supplemented group (ScS) and intraperitoneal supplemented group (IpS)) showed these results. RESULTS: Protein Sc values were (47.8%) lower than Ip groups. Sc group fat content was (65.16%) higher than Ip groups. Liver glycogen value for Sc groups was (38.4%) higher than Ip groups. Muscle glycogen value for Sc groups were (2.75 times) higher than Ip groups. Corticosterone and insulin values were lower (44.53%) and higher (45.94%), respectively, in Sc when compared with Ip groups. Glucose and lactate values for ScS were the lowest (61.7% and 41.53%) compared to other groups. ScC glutamine value was the highest (40.8%) of all groups. Glutamate Sc values were (42.65%) lower than Ip groups. Sc groups showed greater survival time compared with Ip groups. ScS group showed 100% increase in survival time when compared with ScC. CONCLUSIONS: HMbeta supplementation can increase survival time and promotes metabolic changes in cancer-bearing animals, but it seems to work in a time-dependent manner.
Subject(s)
3-Hydroxybutyric Acid/administration & dosage , Body Composition/drug effects , Carcinoma 256, Walker/metabolism , Energy Metabolism/drug effects , Glycogen/metabolism , Adipose Tissue/metabolism , Animals , Body Composition/physiology , Cachexia/metabolism , Cachexia/mortality , Cachexia/prevention & control , Carcinoma 256, Walker/mortality , Dietary Supplements , Disease Models, Animal , Energy Metabolism/physiology , Injections, Intraperitoneal , Injections, Subcutaneous , Liver Glycogen/metabolism , Male , Proteins/metabolism , Rats , Rats, Wistar , Survival Rate , Time FactorsABSTRACT
Os ácidos graxos säo o principal substrato energético utilizado pelas fibras musculares durante a realizaçäo de um exercício de intensidade submáxima e longa duraçäo. A instalaçäo da fadiga periférica durante este tipo de atividade está relacionada à reduçäo dos estoques endógenos de carboidrato. A adoçäo da suplementaçäo lipídica visa maximizar a utilizaçäo deste tipo de substrato em detrimento aos estoques de carboidrato, promovendo assim, o efeito poupador de glicogênio ("sparing effect"). A suplementaçäo lipídica para atividades de "endurance" pode ser classificada em duas principais estratégias: a) elevaçäo aguda dos ácidos graxos no plasma e b) administraçäo de dietas hiperlipídicas. Existe, contudo, muita controvérsia em relaçäo aos possíveis efeitos benéficos ou deletérios deste tipo de suplementaçäo para atletas. O objetivo deste trabalho foi revisar a literatura sobre os efeitos da suplementaçäo lipídica sobre o desempenho físico tento de animais como de humanos