Efeitos agudos dos extratos hidroalcoólicos do alho (Allium sativum L.) e do capim-limão (Cymbopogon citratus (DC) Stapf) sobre a pressão arterial média de ratos anestesiados / Acute effects of Allium sativum L. and Cympobongon citratus (DC) Stapf hydroalcoholic extracts on arterial blood pressure of anesthetized rats

Este trabalho objetivou verificar os efeitos da aplicação aguda endovenosa dos extratos hidroalcoólicos de Allium sativum e de Cymbopogon citratus sobre a pressão arterial de ratos. Foram usados Rattus novergicus albinus, n=7, anestesiados, traqueostomizados e canulados através da veia jugular e da artéria carótida. Foram injetadas doses de 1 mg dos extratos separadamente e em associação (1mg + 1mg), em volumes de 0,2mL. A pressão arterial média (PAM) foi registrada com um sistema Biopac, modelo MP100. O Allium sativum diminuiu a PAM de 124±2 mmHg, no controle, para 108±2 mmHg aos 15s. Da mesma forma, o Cymbopogon citratus diminuiu a PAM de 122±2 mmHg, no controle, para 106± 2 mmHg aos 15s. A associação de ambos também diminuiu a PAM de 126±3 mmHg, no controle, para 113±3 mmHg aos 15s. Os efeitos das duas plantas foram iguais e não foram incrementados quando associadas.

This work aimed to verify the effects of acute intravenous applications of Allium sativum and Cymbopogon citratus hydroalcoholic extracts on arterial blood pressure of anesthetized rats. Adult male rats (Rattus novergicus albinus), n=7, were used. The rats were anesthetized, tracheotomy and cannulation of both jugular and carotid were carried out. The injected doses were 1 mg separately as well as the association of both extracts, in volumes of 0,2 mL. The mean arterial blood pressure (MAP) was recorded with a Biopac System, model MP100. The Allium sativum decreased the MAP only from 124±2 mmHg (control) to 108±2 mmHg at 15s. The Cymbopogon citratus also decreased the MAP from 122±2 mmHg (control) to 106±2 mmHg after 15s. The 1mg of Allium sativum + 1mg of Cymbopogon citratus also decreased the MAP from 126±3 mmHg (control) to 113±3 mmHg after 15s. The effects of the two plants were the same and were not increased when in association.

Lack of hypophosphatemic effect on glucose uptake, lactate and pyruvate release by the normal rat perfused hind-limb

In previous experiments, it was observed that in the perfused hind-limb of phosphorus deficient rats there was a faster utilization of glucose when compared with preparations obtained from ad-libitum fed rats but similar to that obtained from pair-weighed rats. A greater release of lactate under the influence of insulin and a marked spontaneous and insulin induced liberation of pyruvate was registered in the perfused hind-limb of the phosphorus deficient rat. Since a hypophosphatemic medium was employed, we though it would be interesting to study the effect of low perfusate Pi in normal rat hind-limb preparations and, additionally, to observe it fast changes in the level of medium orthophosphate from normal to low values and viceversa were able to determine changes in glucose uptake and lactate and pyruvate release. In one group of experiments, the hind-limb of normal rats was perfused successively with orthophosphate deprived medium for thirty minutes in each stage. In another group of experiments, the first stage was carried out with normal. Pi medium, the second with orthophosphate deprived medium, and the third with normal Pi medium; each stage lasted thirty minutes. In all the experiments there was a gradual release of orthophosphate. The glucose uptake was not modified by the fast changes in the medium Pi nor were significant differences in lactate and pyruvate release observed, which showed clear increases in all stages. It is concluded that hypophosphatemia alone is not sufficient to obtain greater increases of lactate and pyruvate release; it is also required that the hind-limb preparations be obtained from ..

Glucose uptake orthophosphate exchange lactate and pyruvaterelease of perfused rat hind-limb during phosphorus deficiency

This experimental work was carried out on perfused skinned hind-limbs from three groups of rats: fed-ad-libitum (FAL), phosphorus deficient (PD) and pair-weighed (PW), all of them fasted for 24 hours before the experiments. The perfusate was prepared using KRB solution to which was added bovine albumin (3 g.%), glucose (180 mg/dl), orthophosphate (0.5 mg/dl) and approximately 16-18 per cent of fresh washed rats erythrocytes. pH was adjusted to 7.40. The medium was bubbled with hunid O2-CO2 gas mixture (95/5%). Initial perfusate volume was 90 ml. 32Pi (0.5*Ci/ml) was incorporated to the medium at -15 minutes time.Parameters measured were: perfusate glucose, perfusate plasma Pi, perfusate 32Pi, perfusate plasma Pi relative specific activity, perfusate lactate and perfusate pyruvate. Samples were obtained every 15 minutes up to 90 minutes. Insulin (200 *U/ml) was added to perfusate as a bolus at 0 minutes time, in the experiments in which the effect to the hormone was appraised. The spontaneous glucose uptake was greater in the PD group than in the FAL group, but no significant difference was found between PD and PW. Insulin increased the glicose uptake in the three groups, but the difference between PD and the other two groups was not significant. The perfusate plasma Pi rose gradually in all groups. In the stage 0-30 minutes hypophosphatemia was still present, and the increase in glucose uptake determined by insulin was not significantly different from the spontaneous incorporation of the hexose to the preparations in the PD group. The spontaneous Pi release to the medium by the preparations was not significantly differ..

The effect of the omission of perfusate orthophospahate on lactate gluconeogenesis and Pi exchange in the perfused fasted rat liver

En la estandardización de un método para la perfusión del hígado de la rata. Hems et al., observaron que al omitir el fosfato del medio tenía lugar una reducción de la neoglucogénesis a partir de lactado, en un 50%. Con el propósito de utilizar esta técnica para producir deplección aguda de fosfato en el hígado, se realizaron experimentos similares con un perfusado que sólo difería por contener aproximadamente el doble de eritrocitos humanos (20-22%). Los glóbulos rojos humanos usados habían sido envejecidos 4-5 semanas en condiciones de banco de sangre. Hems y colaboradores encontraron que en estas condiciones los hematíes pierden su poder glicolítico y mantienen su capacidad para transportar oxígeno. Con el fin de acentuar la depleción de Pi, los hígados de las ratas previamente mantenidas en ayunas por 24 h. fueron perfundidos con medio sin fosfato por 75 min. y luego transferidos a otro aparato de perfusión también privado de Pi en el cual se mantuvo al órgano por 120 min. adicionales. A los 15 min. de haber montado el hígado para la segunda perfusión 1 micronCI de Pi de alta actividad por ml, se añadió al medio y a los 15 min. se tomó la muestra cero, de allí en adelante se obtuvieron muestras adicionales cada 15 min. La omisión de fosfato del medio no redujo la gluconeogenesis a partir del lactado ni aún añadiendo glucagon para estimular ese proceso. En los experimentos de perfusión del hígado y en los blancos en los cuales se hizo circular el perfusado en ausencia del hígado, se observó que el valor inicial de Pi era alrededor de 50% del obtenido con el medio standard, lo que indica que la liberación de fosfato por los hematíes y por el hígado no permitió trabajar con el medio libre del anión. La hemólisis fue mínima y las muestras fueron esfriadas rápidamente para evitar desintegración de compuestos fosforados. Se observó también que los glóbulos rojos humanos envejecidos por 4-5 semanas no pierden su poder glicolítico. En la depleción parcial del fosfato obtenida en nuestros experimentos, el lactado y con mayor intensidad el lactado...

Inhibition of the glucagon induced incorporation of orthophosphate into the liver by gluconeogenic blockers

Hígados aislados de ratas alimentadas, fueron perfundidos con un medio preparado a partir de solución KRB a la cual se añadieron: seroalbúmina bovina, 3g/dl; glucosa, 90 mg/dl; ortofosfato para obtener una concentración en el plasma de 1 mg/dl; 18 por ciento de glóbulos rojos de rata lavados; pH, 7.40, fase gaseosa O2 95%-CO2 5%. Flujo 36 ml/min. Temperatura, 37-C. Volumen del perfusado 70 ml. 0,5 micronCi de 32P-ortofosfato por ml. fueron añadidos al perfusado diez minutos antes de montar el hígado: el tiempo, 15 minutos después de montar el órgano, se tomó como punto cero. En los experimentos en los cuales se emplearon los bloqueadores de la neoglucogénesis ( quinolinato 1,68 mM o aminoóxi-acetato 0.2 mM) éstos fueron añadidos al perfusado al tiempo 15 min. el glucagon, cuando fue administrado, se empleó en inyección continua entre 45 y 90 min. (20 microngm). Se tomaron muestras cada 15 minutos hasta 120 minutos, que se recogieron en tubos enfriados en hielo. Glucosa en el perfusado, Pi en el plasma, 32Pi en perfusado y actividad específica del Pi plasmático fueron los parámetros determinados. Se calcularon Deltas a partir de 45 min. Los valores de glucosa y de Pi plasmático se corrigieron a partir de blancos obtenidos, haciendo circular el perfusado en ausencia del hígado y los resultados se expresaron por 10g de hígado fresco