ABSTRACT
BACKGROUND: To study whether Pseudomonas aeruginosa may directly trigger peroxidation of polyunsaturated fatty acids, since lipid peroxidation is a mechanism involved in the pathogenesis of sepsis. METHODS: Gamma-linolenic acid (GLA) was administered intravenously at a dose of 25mg/kg in an infusion time of 10 minutes to seven male rabbits. Blood samples were collected from the hepatic veins and from the carotid artery at regular time intervals. One clinical isolate was ex vivo incubated with the serum derived from the latter samples and concentrations of malondialdehyde (MDA) were determined during incubation in the growth medium by the thiobarbiturate assay. RESULTS: Elevated concentrations of MDA compared to their basal levels were found over the first three hours of incubation in the presence of samples collected 30 to 60 minutes after the end of the infusion of GLA. After infusion of GLA concentrations of arachidonic acid in the serum increased to concentrations comparable to those detected in sepsis. CONCLUSION: Direct triggering of lipid peroxidation by nosocomial isolates might be proposed as a pathogenetic mechanism of sepsis.
Subject(s)
Animals , Arachidonic Acid/blood , Cross Infection/blood , Lipid Peroxidation , Male , Malondialdehyde/blood , Pseudomonas aeruginosa/metabolism , Rabbits , gamma-Linolenic Acid/administration & dosageABSTRACT
Se estudió el efecto de una dieta suplementada con ácido gama-linolénico (18:3 n-6, GLA) sobre el crecimiento de un tumor mucoepidermoide de pulmón humano (HLMC) implantado en ratones atímicos y sobre la captación por el mismo de lipoproteínas de baja densidad humana marcadas con 99mTc (99mTc-LDL). Los ratones portadores de HLMC se dividieron en dos grupos experimentales, uno que recibió dieta control (dieta C) y el otro, dieta suplementada con GLA (dieta GLA), durante tres semanas. Se observó una marcada inhibición del crecimiento tumoral al finalizar el tratamiento. La dieta enriquecida en GLA indujo cambios en la composición en ácidos grasos totales del tumor y del plasma e hígado de los ratones huéspedes. Los tumores de los animales alimentados con ambas dietas captaron radiactividad de las 99mTc-LDL y no se observaron diferencias significativas en la relación entre la captación por el tumor y por el hígado y riñón de los animales huéspedes. Los resultados obtenidos utilizando este modelo experimental sugieren que el efecto inhibitorio del GLA sobre el crecimiento tumoral es independiente de la captación de LDL por parte del tumor.
Subject(s)
Humans , Female , Mice , Animals , gamma-Linolenic Acid/administration & dosage , Carcinoma, Mucoepidermoid/pathology , Diet , Food, Fortified , Lipoproteins, LDL/blood , Lung Neoplasms/pathology , Fatty Acids/chemistry , Analysis of Variance , Lipoproteins, LDL , Mice, Nude , Neoplasm Transplantation , Organotechnetium CompoundsABSTRACT
The effects of a dietary alphalinolenic acid (18: 3w3) deficiency on reproduction and post natal growth in rats during 3 successive generations were studied. Female rats received respectively a diet with sunflower oil at 10 (deficient diet) or a diet with soya oil at 10 (control diet). The results showed that in our experimental conditions deficient diet affects: fecundity, fertility, post natal growth and cause a high rates of perinatal mortality from birth to post partum day 3: Perinatal mortality increased with successive gestation from 14.6 to 18.6 compared with the survival of control. The fatty acid composition of placenta phospholipids and milk lipids reflected the nature of the dietary oil. The possibility that 18: 3w3 might function in a way different from the EFA role of 18: 2w6 in reproduction at least in rats has been discussed.