RESUMEN
A fractional factorial design 2(5-1) was used to evaluate the effect of temperature, pH, and concentrations of yeast extract, tryptone and Nitsch's trace elements on the biomass, total carotenoids and protection against singlet oxygen by carotenoid extracts of the bacterium Thermus filiformis. In addition, the carotenoid composition was determined by high-performance liquid chromatography connected to a diode array and mass spectrometer detectors (HPLC-DAD-MS/MS). The production of biomass ranged from 0.113 to 0.658 g/L, the total carotenoid from 137.6 to 1,517.4 mg/g and the protection against singlet oxygen from 4.3 to 85.1 %. Results of the fractional factorial design showed that temperature had a negative effect on biomass production and a positive effect on carotenoid content and protection against singlet oxygen, besides, high levels of pH value, concentrations of yeast extract and tryptone had a positive effect on biomass production only at lower temperatures. The main carotenoids of T. filiformis were thermozeaxanthins. In the tested conditions, changes in the levels of the variables influenced the biomass, carotenoid production, and protection against singlet oxygen, although they did not influence the carotenoid profile. The results of this study provide a better understanding on the interactions among certain nutritional and cultivation conditions of a thermophile bacterium, Thermus filiformis, on biomass and carotenoid amounts, as well as on the antioxidant capacity.
Asunto(s)
Biomasa , Cromatografía Liquida , Carotenoides/análisis , Yodopiraceto/análisis , Oxígeno Singlete/análisis , Thermus/genética , Thermus/aislamiento & purificación , Levaduras , Técnicas Químicas Combinatorias , Concentración de Iones de Hidrógeno , MétodosRESUMEN
The intravenous injection of cimetidine in a dose of 20 mg/kg enhanced verografine and iodamide excretion in chronic canine experiments. The higher verografine and iodamide excretion was due to their increased renal tubular secretion. In dogs, cimetidine unchanged the secretion of cardiotrast, a test agent for anionic transport. Possible extrarenal mechanisms of action of cimetidine on verografine and iodamide transport were also examined.
Asunto(s)
Cimetidina/farmacología , Diatrizoato de Meglumina/metabolismo , Iodamida/metabolismo , Riñón/efectos de los fármacos , Animales , Cimetidina/administración & dosificación , Diatrizoato de Meglumina/análisis , Diuresis/efectos de los fármacos , Perros , Interacciones Farmacológicas , Tasa de Filtración Glomerular/efectos de los fármacos , Iodamida/análisis , Yodopiraceto/análisis , Yodopiraceto/metabolismo , Riñón/metabolismo , Factores de TiempoRESUMEN
In chronic experiments on dogs it was shown that verografin and iodamide are excreted from the body not only by filtration but by tubular excretion as well. The maximal transport of verografin and iodamide is significantly lower than that of cardiotrast. In experiments on rats similar results were obtained. Concurrent administration of verografin and iodamide with cardiotrast decreases their excretion in the urine in rats that is probably due to competition for the common transport system in the epithelium of renal tubules.
Asunto(s)
Diatrizoato de Meglumina/farmacocinética , Iodamida/farmacocinética , Yodobenzoatos/farmacocinética , Yodopiraceto/farmacocinética , Riñón/metabolismo , Animales , Transporte Biológico/efectos de los fármacos , Diatrizoato de Meglumina/análisis , Perros , Interacciones Farmacológicas , Inulina/farmacocinética , Iodamida/análisis , Yodopiraceto/análisis , Riñón/efectos de los fármacos , RatasAsunto(s)
Líquido Amniótico/metabolismo , Feto/metabolismo , Yodopiraceto/metabolismo , Tráquea/embriología , Líquido Amniótico/análisis , Animales , Líquidos Corporales/análisis , Cateterismo , Femenino , Haplorrinos , Inyecciones Intravenosas , Isótopos de Yodo , Yodopiraceto/administración & dosificación , Yodopiraceto/análisis , Yodopiraceto/sangre , Ligadura , Métodos , Placenta , Embarazo , Tráquea/análisis , Tráquea/cirugíaRESUMEN
1. Sheep, which had access to a solution containing 1.3% sodium chloride as their sole source of drinking water for 6 months or more, were infused with a hypertonic solution (10%) of sodium chloride, and their ability to tolerate this salt load was compared with that of a similar group of sheep which drank only rain water.2. The sheep which drank the rain water were often affected by the infusion and exhibited signs resembling potassium deficit. No such signs were apparent in the animals which consumed saline water.3. Glomerular filtration rates were increased in all sheep by the hypertonic saline infusion, the increases being greater in the sheep which were maintained on the saline water. Effective renal plasma flow rates, though extremely variable, behaved in a similar manner.4. Plasma values for sodium and chloride were increased in all sheep, but remained at a higher level for a longer period in the sheep which consumed rain water. The diuresis produced by hypertonic saline appeared to persist for a longer period in the sheep which drank rain water, while the excretion of sodium and chloride tended to be greater in the sheep maintained on saline water.5. Plasma potassium was reduced in all sheep and urinary excretion of potassium increased. The latter response was more pronounced in the sheep which drank the rain water.6. Filtered loads of sodium, chloride and potassium were greater in the sheep which were accustomed to drinking saline water. However, the amounts of potassium excreted were greater than those filtered in the rain water sheep and less than those filtered in the sheep which drank saline water. It therefore seems that secretion of potassium into the kidney tubules predominated in the former group and reabsorption prevailed in the latter.7. Reabsorption of free water in excess of solute was greater in the kidney tubules of the sheep which drank saline water.8. Increased blood volume and greater dilution of plasma proteins occurred in the sheep which drank rain water.