Effect of pre-administered flurbiprofen axetil on the EC50 of propofol during anesthesia in unstimulated patients: a randomized clinical trial / Efeito da pré‐ administração de flurbiprofeno axetil na CE50 do propofol durante anestesia em pacientes não estimulados: estudo clínico randomizado

Abstract Background and objectives Preoperative use of flurbiprofen axetil (FA) is extensively adopted to modulate the effects of analgesia. However, the relationship between FA and sedation agents remains unclear. In this study, we aimed to investigate the effects of different doses of FA on the median Effective Concentration (EC50) of propofol. Methods Ninety-six patients (ASA I or II, aged 18-65 years) were randomly assigned into one of four groups in a 1:1:1:1 ratio. Group A (control group) received 10 mL of Intralipid, and groups B, C and D received 0.5 mg.kg−1, 0.75 mg.kg−1 and 1 mg.kg−1 of FA, respectively, 10 minutes before induction. The depth of anesthesia was measured by the Bispectral Index (BIS). The "up-and-down" method was used to calculate the EC50 of propofol. During the equilibration period, if BIS ≤ 50 (or BIS > 50), the next patient would receive a 0.5 µg.mL−1-lower (or -higher) propofol Target-Controlled Infusion (TCI) concentration. The hemodynamic data were recorded at baseline, 10 minutes after FA administration, after induction, after intubation and 15 minutes after intubation. Results The EC50 of propofol was lower in Group C (2.32 µg.mL−1, 95% Confidence Interval [95% CI] 1.85-2.75) and D (2.39 µg.mL−1, 95% CI 1.91-2.67) than in Group A (2.96 µg.mL−1, 95% CI 2.55-3.33) (p = 0.023, p = 0.048, respectively). There were no significant differences in the EC50 between Group B (2.53 µg.mL−1, 95% CI 2.33-2.71) and Group A (p > 0.05). There were no significant differences in Heart Rate (HR) among groups A, B and C. The HR was significantly lower in Group D than in Group A after intubation (66 ± 6 vs. 80 ± 10 bpm, p < 0.01) and 15 minutes after intubation (61 ± 4 vs. 70 ± 8 bpm, p < 0.01). There were no significant differences among the four groups in Mean Arterial Pressure (MAP) at any time point. The MAP of the four groups was significantly lower after induction, after intubation, and 15 minutes after intubation than at baseline (p < 0.05). Conclusion High-dose FA (0.75 mg.kg−1 or 1 mg.kg−1) reduces the EC50 of propofol, and 1 mg.kg−1 FA reduces the HR for adequate anesthesia in unstimulated patients. Although this result should be investigated in cases of surgical stimulation, we suggest that FA pre-administration may reduce the propofol requirement when the depth of anesthesia is measured by BIS.

Resumo Justificativa e objetivos A administração pré‐operatória de Flurbiprofeno Axetil (FA) é amplamente usada para a modulação da analgesia. No entanto, a relação entre FA e fármacos sedativos permanece obscura. Neste estudo, nosso objetivo foi investigar os efeitos de diferentes doses de FA na Concentração Efetiva mediana (CE50) do propofol. Métodos Noventa e seis pacientes (ASA I ou II, com idades de 18-65 anos) foram alocados aleatoriamente em quatro grupos na proporção de 1:1:1:1. Dez minutos antes da indução, o Grupo A (grupo controle) recebeu 10 mL de Intralipid, enquanto os grupos B, C e D receberam FA na dose de 0,5 mg.kg‐1; 0,75 mg.kg‐1 e 1 mg.kg‐1, respectivamente. A profundidade da anestesia foi medida pelo Índice Bispectral (BIS). O método up‐and‐down foi usado para calcular a CE50 do propofol. Durante o período de equilíbrio, se o valor do BIS fosse ≤ 50 ou BIS > 50, o próximo paciente tinha a infusão de propofol ajustada para uma concentração alvo‐controlada 0,5 µg.mL‐1 inferior ou superior, respectivamente. Os dados hemodinâmicos foram registrados no início do estudo, 10 minutos após a administração de FA, após a indução, após a intubação e 15 minutos após a intubação. Resultados A CE50 do propofol foi menor no Grupo C (2,32 µg.mL‐1, Intervalo de Confiança de 95% [95% IC] 1,85-2,75) e D (2,39 µg.mL‐1, 95% IC 1,91-2,67) do que no Grupo A (2,96 µg.mL‐1; 95% IC 2,55-3,33) (p = 0,023, p = 0,048, respectivamente). Não houve diferenças significantes na CE50 entre o Grupo B (2,53 µg.mL‐1, 95% IC 2,33-2,71) e o Grupo A (p > 0,05). Não houve diferenças significantes na Frequência Cardíaca (FC) entre os grupos A, B e C. A FC foi significantemente menor no grupo D do que no grupo A após a intubação (66 ± 6 vs. 80 ± 10 bpm, p < 0,01) e 15 minutos após a intubação (61 ± 4 vs. 70 ± 8 bpm, p < 0,01). Não houve diferenças significantes entre os quatro grupos na Pressão Arterial Média (PAM) em qualquer momento. A PAM dos quatro grupos foi significantemente menor após a indução, após a intubação e 15 minutos após a intubação do que na linha de base (p < 0,05). Conclusão FA em altas doses (0,75 mg.kg‐1 ou 1 mg.kg‐1) reduz a CE50 do propofol, e 1 mg.kg‐1 de FA reduz a FC durante níveis adequados de anestesia em pacientes não estimulados. Embora esse resultado deva ser investigado na presença de estimulação cirúrgica, sugerimos que a pré‐administração de FA pode reduzir a necessidade de propofol durante anestesia cuja profundidade seja monitorada pelo BIS.

Detoxification effects of long-chain versus a mixture of medium- and long-chain triglyceride-based fat emulsion on propafenone poisoning

In the present study, we aimed to compare the detoxifying effects of two fat emulsions containing either long-chain triglyceride or a mixture of medium-chain and long-chain triglycerides in the propafenone-poisoned rat model. Rats were randomly divided into 3 groups according to the fat emulsions used: long-chain triglyceride-based fat emulsion (LL) group; medium-chain and long-chain triglyceride-based fat emulsion (ML) group; normal saline (NS) group. Propafenone was continuously pumped (velocity=70 mg/kg per h) until the mean blood pressure dropped to 50% of basal level. Then, LL/ML fat emulsions or NS was intravenously infused instantly with a loading-dose (1.5 mL/kg) and a maintenance dose (0.25 mL/kg per min) for 1 h. Subsequently, the propafenone was added to plasma (3.5 μg/mL) in vitro, mixed with three doses of LL or ML (1, 2, or 4%). Finally, after centrifugation, the concentration of propafenone was measured. Rats treated with LL exhibited accelerated recovery, characterized by higher blood pressure and heart rate. Rats in both the LL and ML groups demonstrated decreased propafenone in plasma (time-points: 15, 25, and 60 min). However, rats that received LL showed lower propafenone in myocardial tissue at the end of detoxification treatment. Rats in the ML group had the lowest value of pH, the minimum content of HCO3-, and the highest production of lactic acid at the end. In the in vitro experiments, propafenone decreased more dramatically in the LL group compared to the ML group. Long-chain triglyceride fat emulsion had a better effect on treating propafenone poisoning in rats.

Effects of propofol in lipid-based emulsion and in microemulsion on the incidence of endothelial lesion in rabbits

PURPOSE: To compare the incidence of endothelial injury after single-dose or continuous propofol infusion in conventional lipid-based emulsion (LE) versus microemulsion (ME). METHODS: Forty-two rabbits (2.5-4.5 Kg) were randomly allocated into seven groups of six animals each: SHAM- surgical treatment alone; Bolus Control Group - 3 mL-intravenous (IV) bolus of saline; Continuous Infusion Control Group - 3 mL- IV bolus of saline followed by a continuous infusion of 0.2 ml/kg/min for 60 min; Bolus LE Propofol Group - IV bolus of LE propofol (3 mg/kg); Bolus ME Propofol Group - IV ME propofol bolus (3 mg/kg); Continuous LE Propofol Group - IV LE propofol bolus (3 mg/kg) followed by a continuous infusion of 0.2 ml/kg/min for 60 min; Continuous ME Propofol Group - IV ME propofol bolus (3 mg/kg) followed by a continuous infusion of 0.2 ml/kg/min for 60 min. RESULTS: There were no statistically significant differences between the studied groups in blood pressure, in central venous pressure and in the biochemical profile. No significant differences were found in inflammatory mediators and in tissue analysis between the two emulsions. CONCLUSION: Microemulsion and lipid-based emulsion propofol had similar inflammatory, biochemical and microscopy profiles. Thus, microemulsion propofol can be used as an alternative to lipid-based emulsion propofol.

Pressão arterial, respostas metabólicas e autonômicas à insulina e infusão de intralipid® em pacientes chagásicos / Blood pressure, metabolic and autonomic responses to insulin and intralipid® infusion in chagasic patients / Presión arterial, respuestas metabólicas y autonómicas a la insulina e infusión de intralipid® en pacientes chagásicos

FUNDAMENTO: Infusão de intralipid e heparina resulta em aumento da pressão arterial e também em anormalidades autonômicas em indivíduos normais e hipertensos. OBJETIVO: Avaliar a sensibilidade a insulina e o impacto da infusão de intralipid e de heparina (ILH) sobre a resposta hemodinâmica, metabólica e autonômica em pacientes com a forma indeterminada da doença de Chagas. MÉTODOS: Doze pacientes com a forma indeterminada da doença de Chagas e 12 voluntários saudáveis foram avaliados. RESULTADOS: A pressão arterial basal e a frequência cardíaca foram semelhantes nos dois grupos. Os níveis plasmáticos de noradrenalina encontravam-se ligeiramente aumentados no grupo de pacientes chagásicos. Após o Teste de Tolerância a Insulina (TTI), houve um declínio significativo na glicose dos dois grupos. A Infusão de ILH resultou em aumento da pressão arterial em ambos os grupos, mas não houve nenhuma mudança significativa na noradrenalina plasmática. O componente de Baixa Frequência (BF) mostrou-se semelhante e aumentou de forma semelhante em ambos os grupos. O componente de Alta Frequência (AF) apresentou-se menor no grupo chagásico. CONCLUSÃO: Pacientes com forma indeterminada da doença de Chagas apresentaram aumento da atividade simpática no momento basal e uma resposta inadequada à insulina. Eles também tiveram um menor componente de alta frequência e sensibilidade barorreflexa prejudicada no momento basal e durante a infusão de intralipid e heparina.

BACKGROUND: Intralipid and heparin infusion results in increased blood pressure and autonomic abnormalities in normal and hypertensive individuals. OBJECTIVE: To evaluate insulin sensitivity and the impact of Intralipid and heparin (ILH) infusion on hemodynamic, metabolic, and autonomic response in patients with the indeterminate form of Chagas' disease. METHODS: Twelve patients with the indeterminate form of Chagas' disease and 12 healthy volunteers were evaluated. RESULTS: Baseline blood pressure and heart rate were similar in both groups. Plasma noradrenaline levels were slightly increased in the Chagas' group. After insulin tolerance testing (ITT), a significant decline was noted in glucose in both groups. ILH infusion resulted in increased blood pressure in both groups, but there was no significant change in plasma noradrenaline. The low-frequency component (LF) was similar and similarly increased in both groups. The high-frequency component (HF) was lower in the Chagas' group. CONCLUSION: Patients with the indeterminate form of Chagas' disease had increased sympathetic activity at baseline and impaired response to insulin. They also had a lower high-frequency component and impaired baroreflex sensitivity at baseline and during Intralipid and heparin infusion.

FUNDAMENTO: La Infusión de intralipid® y de heparina trae como resultado un aumento de la presión arterial y también de las anormalidades autonómicas en los individuos normales e hipertensos. OBJETIVO: Evaluar la sensibilidad a la insulina y el impacto de la infusión de intralipid® y de heparina (ILH) sobre la respuesta hemodinámica, metabólica y autonómica en pacientes con la forma indefinida de la Enfermedad de Chagas. MÉTODOS: Fueron evaluados doce pacientes con la forma indefinida de la Enfermedad de Chagas y 12 voluntarios sanos. RESULTADOS: La presión arterial basal y la frecuencia cardíaca fueron similares en los dos grupos. Los niveles plasmáticos de noradrenalina estaban ligeramente más elevados en el grupo de pacientes chagásicos. Después del Test de Tolerancia a la Insulina (TTI), se produjo una ostensible disminución en la glucosa de los dos grupos. La Infusión de ILH trajo como consecuencia el aumento de la presión arterial en ambos grupos, pero no hubo ningún cambio significativo en la noradrenalina plasmática. El componente de Baja Frecuencia (BF), fue similar y aumentó de forma parecida en ambos grupos. El componente de Alta Frecuencia (AF) se presentó con un menor nivel en el grupo chagásico. CONCLUSIONES: Los pacientes con una forma indeterminada de la Enfermedad de Chagas, presentaron un aumento en la actividad simpática al momento basal y una respuesta inadecuada a la insulina. También tuvieron un menor componente de alta frecuencia y de sensibilidad barorrefleja, que fue perjudicado en el momento basal y durante la infusión de intralipid® y heparina.

Metabolism of a lipid nanoemulsion resembling low-density lipoprotein in patients with grade III obesity

Introduction: Obesity increases triglyceride levels and decreases high-density lipoprotein concentrations in plasma. Artificial emulsions resembling lipidic plasma lipoprotein structures have been used to evaluate low-density lipoprotein metabolism. In grade III obesity, low density lipoprotein metabolism is poorly understood. Objective: To evaluate the kinetics with which a cholesterol-rich emulsion (called a low-density emulsion) binds to low-density lipoprotein receptors in a group of patients with grade III obesity by the fractional clearance rate. Methods: A low-density emulsion was labeled with [14C]-cholesterol ester and [³H]-triglycerides and injected intravenously into ten normolipidemic non-diabetic patients with grade III obesity [body mass index higher than 40 kg/m²] and into ten non-obese healthy controls. Blood samples were collected over 24 hours to determine the plasma decay curve and to calculate the fractional clearance rate. Results: There was no difference regarding plasma levels of total cholesterol or low-density lipoprotein cholesterol between the two groups. The fractional clearance rate of triglycerides was 0.086 ± 0.044 in the obese group and 0.122 ± 0.026 in the controls (p = 0.040), and the fractional clearance rate of cholesterol ester (h-1) was 0.052 ± 0.021 in the obese subjects and 0.058 ± 0.015 (p = 0.971) in the controls. Conclusion: Grade III obese subjects exhibited normal low-density lipoprotein removal from plasma as tested by the nanoemulsion method, but triglyceride removal was slower.

Emulsión lipídica: ¿nuevo paradigma para el tratamiento de la toxicidad sistémica por anestésicos locales? / Lipidic emulsion: a new paradigm for the treatment of systemic toxicity due to local anesthetics?

La toxicidad sistémica por sobredosis de anestésico local es una complicación rara pero potencialmente devastadora de la anestesia regional y central neuraxial. El colapso cardiovascular que sigue a la toxicidad sistémica por sobredosis de anestésico local, especialmente la bupivacaína, es extremadamente difícil de tratar usando los fármacos estándares de resucitación, con el potencial resultado de paro cardíaco refractario a esta acción. La terapia con emulsión lipídica puede restaurar rápidamente la circulación luego del colapso cardiovascular inducido por anestésicos locales. Modelos experimentales de toxicidad por anestésicos locales han mostrado un retorno acelerado de la función cardíaca espontánea posterior a una infusión lipídica, tanto en animales intactos como en corazones aislados. Varios reportes de caso se refieren a la extensión de estos hallazgos al área clínica, citando rápidas resucitaciones con lípidos de sujetos con paro cardíaco luego de una anestesia regional. El tratamiento precoz con emulsión lipídica de pacientes con signos neurológicos puede prevenir la parada cardíaca o acelerar el retorno del latido cardíaco espontáneo. Cuando se presenta un individuo con signos de severa toxicidad por anestésico local (inconsciencia, convulsiones tónico-clónicas, colapso cardiovascular), se debe suspender la inyección de anestésico local, pedir ayuda, mantener la vía aérea permeable, administrar oxígeno al 100 por ciento, mantener una adecuada ventilación pulmonar, lograr el control de las convulsiones (benzodiazepinas, tiopental o propofol en dosis incrementales), comenzar una reanimación, administrar bolo intravenoso de Intralipid ® 20 por ciento, 1,5 ml/kg en 1 minuto, continuar RCP, comenzar la infusión intravenosa de Intralipid ® 20 por ciento,0,25 ml/kg.min, continuar RCP y repetir el bolo dos veces con intervalos de 5 minutos si no se restauró una adecuada circulación...

Systemic toxicity caussed by overdose of local anesthetics is a rare complication but it is potentially devastating in regional and central neuraxial anesthesia. The cardiovascular collapse that follows systemic toxicity due to local anesthetics, particularly bupivacaine, is extremely hard to treat with standard resuscitation drugs, with the potential result of treatment-resistant cardiac arrest. Treatment with lipidic emulsion can rapidly restore circulation after cardiovascular collapse induced by local anesthetics. Experimental models of toxicity due to local anesthetics have shown a fast return of spontaneous cardiac function following a lipidic infusion in intact animals as web as in isolated hearts. Several case reports refer to this findings extended to the clinical area, citing fast resuscitation with lipids in patients with cardiac arrest following regional anesthesia. Early treatment with lipidic emulsion of patients with neurological symptoms can prevent cardiac arrest or quicken the return of spontaneous heartbeat. When faced with a patient with signs of severe toxicity due to local anesthetics (unconsciousness, tonic-clonic convulsions, cardiovascular collapse, the following steps must be taken: suspend local anesthetic injection, request help, keep respiratory ducts permeable, supply oxygen at 100 per cent, maintain adequate pulmonary ventilation, control convulsions (benzodiazepine, tiopenthal or propofol in incremental doses), begin cardiopulmonary reanimation, intravenous bolus of Intralipid@ 20 per cent, 1,5 ml/kg in 1 minute, continue CPR and repeat bolus twice at 5 minute intervals if adequate circulation has not been restores. After 5 minutes, increase the rate of infusion to 0,5 ml/kg.min, continue infusion of lipidic emulsion until adequate circulation has be en achieved and continue CPR thraughout the treatment with lipidic emulsion...

A toxicidade sistêmica causada por superdose de anestésico local é uma complicação rara, mas potencialmente devastadora, da anestesia regional e central neuroaxial. O colapso cardiovascular que segue à toxicidade sistêmica por superdose de anestésico local, especialmente a bupivacaína, é extremamente difícil de tratar usando os fármacos padrões de ressuscitação; o resultado potencial é uma parada cardíaca refratária a esta ação. A emulsão lipídica pode restaurar rapidamente a circulação depois de um colapso cardiovascular induzido por anestésicos locais. Modelos experimentais de toxicidade por anestésicos locais mostraram rápida recuperação da função cardíaca espontânea após infusão lipídica, tanto em animais intactos como em corações isolados. Diversos relatórios de caso referidos à extensão destes achados à área clínica citam o uso de lipídeos para a rápida ressuscitação de pacientes com parada cardíaca causada por anestesia regional. O tratamento precoce com emulsão lipídica de pacientes com sinais neurológicas pode prevenir a parada cardíaca ou acelerar o retorno do batimento cardíaco espontâneo. Quando um indivíduo apresenta sintomas de grave toxicidade por anestésico local (inconsciência, convulsões tônico-clônicas, colapso cardiovascular), é necessário suspender a injeção de anestésico local, pedir ajuda, manter a via aérea permeável, administrar oxigênio a 100 por cento, manter uma adequada ventilação pulmonar, controlar as convulsões (benzodiazepinas, tiopental ou propofol em doses incrementais), começar a reanimação cardiopulmonar, administrar bolo intravenoso de Intralipid® 20 por cento, 1,5 ml/kg em 1 minuto, continuar RCP, iniciar infusao intravenosa de Intralipid® 20 por cento, 0,25 ml/kg.min, continuar RCP e repetir duas vezes o bolo, em intervalos de 5 minutos, se nao for restaurada uma adequada circulação...

Efficacy of amphotericin B in a fat emulsion for the treatment of cryptococcal meningitis in AIDS patients

Several formulae have been developed in an attempt to reduce the toxicity of amphotericin B (AmB), but their high costs preclude widespread use. The aim of this study was to evaluate the efficacy of amphotericin B in a fat emulsion, i.e. Intralipid (AmB-IL), in 37 AIDS patients with cryptococcal meningitis (CM). We retrospectively reviewed data collected in a non-comparative open study between January 1999 and December 2001. The therapeutic cure was defined as complete resolution or improvement of the clinical symptoms or complete absence or improvement of the mycological alterations of the CSF. The outcomes were evaluated at 2 weeks, induction phase (IP), and at the end of treatment or consolidation phase (CP) with the last available CSF. Prior to the diagnosis of CM, 72 percent of patients had had one or more OI and 67.57 percent had a concomitant OI. The median CD4-cell count was 32 cells/mm³, the median leukocyte count in the CSF was 29 cells/mm³ and the median cumulative dose of AmB-IL was 1,200 mg (300-2,500). The therapeutic cure was 57.14 percent in the IP and 64.86 percent in the CP. During IP, 9 patients died (24.32 percent) and 4 (10.81 percent) during the CP (p=0.2). Thus, the overall mortality rate was 35.14 percent. AmB-IL, an inexpensive preparation, might be an alternative to conventional AmB. Some questions remain such as its compatibility, stability and level of toxicity. The benefit is especially important in developing countries, where no drugs other than AmB are available to treat systemic fungal infections.

Cinética plasmática de uma microemulsão rica em colesterol (LDE) em pacientes com linfoma de Hodgkin e linfoma não-Hodgkin e estudo preliminar da toxicidade do etoposide associado à LDE / Plasma kinetics of a cholesterol-rich microemulsion (LDE) in patients with Hodgkin's and non-Hodgkin's lymphoma and a preliminary study on the toxicity of etoposide associated with LDE

Diminuição dos níveis da lipoproteína de baixa densidade (LDL) no plasma e da sua remoção plasmática é associada com neoplasias que apresentam aumento da expressão de receptores de LDL e pode permitir o uso da LDL ou de microemulsões ricas em colesterol (LDE) como veículos direcionadores de drogas contra células neoplásicas, uma modalidade de terapia-alvo.

Low plasma low-density lipoprotein (LDL) cholesterol and diminished LDL clearance is associated with cancers with upregulation of LDL receptors and may allow using LDL or cholesterol-rich microemulsions (LDE) as vehicles to target drugs against neoplastic cells. Our aim was to determine whether low LDL cholesterol concentration plus LDE increased clearance occur in lymphomas.

Comparison on pain on injection of a small particle size-lipid emulsion of propofol and standard propofol with or without lidocaine.

Pain on injection, reported in 28-90% of patients, is one of the most described side effects of the intravenous application of propofol. Many different approaches have been used in attempts to minimize propofol induced pain, with varied results. Using a randomized, double-blind protocol design, the author-section pain following the administration of two different particle size formulations of propofol with or without lidocaine in 388 nonpremedicated ASA I-II adult patients scheduled for elective surgery under general anesthesia. Patients were allocated randomly to receive either a small particle size lipid emulsion of propofol (Anepol: average particle size 140.5 nm), or standard propofol (Propofol: average particle size 193.3 nm), by dividing into 4 groups. Group 1 received 2 ml NaCl 0.9% and Propofol, group 11 received 2 ml lidocaine 2% and Propofol, group III received 2 ml NaCl 0.9% and Anepol and group IV received 2 ml lidocaine 2% and Anepol into a dorsal vein of the hand. Pain during propofol injection was evaluated over 5-10 seconds, until loss of conscious, using a four point scale. Sixty-seven patients (69.1%) complained of pain in group 1, as compared with 50%, 41.2% and 39.2% in group II, III and IV (p < 0.05). The reported severity of injection pain was not significantly different between the groups. The authors conclude that small particle size propofol causes less pain on injection than standard propofol.

Influencia da nutriçäo parenteral total em regime glicidico e lipidico sobre a fagocitose de macrofagos de ratos / Effect of fat and fat free total parenteral nutrition on macrophage phagocytosis in rats

O uso de nutricao parenteral total (NPT) tem sido associado a alteracoes anatomicas e funcionais do sistema mononuclear fagocitario. Os efeitos das emulsoes lipidicas parenterais sobre a fagocitose do sistema mononuclear fagocitario ainda sao controversos. O objetivo do presente estudo foi avaliar a influencia da nutricao parenteral total sem lipides e contendo diferentes emulsoes lipidicas sobre a fagocitose de macrofagos. Setenta ratos Wistar com a veia jugular externa cateterizada receberam, por via intravenosa central, diferentes regimes de nutricao parenteral total, isocaloricos (1,16 kcal/mL), isonitrogenados (1,5 g/mL), e isogordurosos (30 a 32 por cento do valor calorico nao proteico) ou dieta oral e foram separados em sete grupos...

Effect of lipid infusion on substrate uptake in soleus muscle of the cat

Se estudió la capacitación de glucosa, ácidos grasos libres (AGL) y ácido láctico (AL) en el músculo soleo de gatos anestesiados y heparinizados. Los animales se estudiaron en tres grupos: 1) gatos enjaulados, 2) gatos "libres", 3) gatos entrenados. Muestras de sangre arterial y del efluente venoso del músculo se tomaron a) en reposo b) después de la contracción muscular c) después de una infusión con Intralipid y d) después de repetir la contracción luego de haber efectuado la infusión. En a) se encontró una correlación directa entre los niveles arteriales de AGL y su captación, en todos los grupos, y una relación directa entre la captación de glucosa y producción de AL en los gatos entrenados. En b) y d) los niveles de AGL estuvieron en relación directa con la producción de AL. En conclusión el soleo del gato en las condiciones estudiadas utiliza preferencialmente los AGL; en la contracción usa el glucógeno con aumento no significativo de la producción de AL. La correlación entre los niveles venosos de AGL y el AL sugiere que los aGL inhiben la entrada de piruvato al ciclo de loa ácidos tricarboxílicos