RESUMEN
A filamentous soil bacterium, strain K202, was isolated from soil where an edible mushroom (Boletopsis leucomelas) was growing and identified as belonging to the genus Streptomyces on the basis of its morphological characteristics and the presence of LL-2, 6-diaminopimelic acid. We studied the existence states of Cs and its migration from extracellular to intracellular fluid in the mycelia of Streptomyces sp. K202. The results indicated that Cs accumulated in the cells through at least 2 steps: in the first step, Cs(+) was immediately and non-specifically adsorbed on the negatively charged cell surface, and in the second step, this adsorbed Cs(+) was taken up into the cytoplasm, and a part of the Cs entering the cytoplasm was taken up by an energy-dependent transport system(s). Further, we confirmed that a part of the Cs(+) was taken up into the mycelia competitively with K(+), because K(+) uptake into the intact mycelia of the strain was significantly inhibited by the presence of Cs(+) in the culture media. This suggested that part of the Cs is transported by the potassium transport system. Moreover, (133)Cs-NMR spectra and SEM-EDX spectra of the mycelia that accumulated Cs showed the presence of at least 2 intracellular Cs states: Cs(+) trapped by intercellular materials such as polyphosphate and Cs(+) present in a cytoplasmic pool.
Asunto(s)
Radioisótopos de Cesio/farmacocinética , Cesio/farmacocinética , Contaminantes del Suelo/farmacocinética , Streptomyces/metabolismo , Transporte Biológico Activo/fisiología , Cesio/análisis , Radioisótopos de Cesio/análisis , Cromatografía en Capa Delgada , Ácido Diaminopimélico/análisis , Espectroscopía de Resonancia Magnética , Microscopía Electrónica de Rastreo , Microscopía Fluorescente , Potasio/metabolismo , Contaminantes del Suelo/análisis , Streptomyces/ultraestructuraRESUMEN
The activity of the cerebral pyruvate recycling pathway and energy metabolism in mice infected with Trichinella spiralis were investigated using (13)C-NMR and in vivo (31)P-NMR spectroscopy, respectively. The (13)C-NMR analysis, using [1,2-(13)C(2)] acetate as a substrate, of whole-brain extracts demonstrated that activity of the pathway increased when T. spiralis infection induced hypoglycemia in the host. The in vivo (31)P-NMR observation showed that the cerebral ATP in normal level sustained throughout this experiment. These findings indicate that the pyruvate recycling pathway plays a role in the energy supply to the host in hypoglycemia induced by T. spiralis infection.
Asunto(s)
Encéfalo/metabolismo , Hipoglucemia/metabolismo , Ácido Pirúvico/metabolismo , Trichinella spiralis/fisiología , Triquinelosis/metabolismo , Animales , Isótopos de Carbono , Metabolismo Energético , Interacciones Huésped-Parásitos , Hipoglucemia/parasitología , Espectroscopía de Resonancia Magnética , Ratones , Ratones Endogámicos ICR , Isótopos de Fósforo , Triquinelosis/complicacionesRESUMEN
We studied the role of benzodiazepine (BDZ) receptors in the commissural subnucleus of the nucleus tractus solitarius (commNTS) in chemoreceptor reflex in urethane-anesthetized, pancronium-immobilized, artificially ventilated and bilaterally vagotomized rats. A BDZ agonist, diazepam (1-4 micromol/kg), administered intravenously reduced resting phrenic nerve activity (PNA) and blood pressure (BP). Stimulation of carotid chemoreceptors induced an increase in PNA and an increase in BP. Diazepam inhibited this chemoreceptor reflex. The effects of intravenous injection of diazepam (4 micromol/kg) on the chemoreceptor reflex were antagonized by microinjection of the BDZ antagonist flumazenil (100 pmol) into the commNTS. Microinjection of flumazenil (100 pmol) alone had no effect on the basal PNA and BP, and the chemoreceptor reflex. These results suggest that BDZ receptors are present in the carotid chemoreceptor reflex pathway in the commNTS and potentiate GABA(A) transmission.
Asunto(s)
Arterias Carótidas/inervación , Células Quimiorreceptoras/fisiología , Receptores de GABA-A/metabolismo , Núcleo Solitario/fisiología , Aferentes Viscerales/fisiología , Animales , Presión Sanguínea/efectos de los fármacos , Presión Sanguínea/fisiología , Arterias Carótidas/fisiología , Células Quimiorreceptoras/citología , Células Quimiorreceptoras/efectos de los fármacos , Diazepam/farmacología , Flumazenil/farmacología , Antagonistas del GABA/farmacología , Masculino , Nervio Frénico/efectos de los fármacos , Nervio Frénico/fisiología , Ratas , Ratas Wistar , Receptores de GABA-A/efectos de los fármacos , Reflejo/efectos de los fármacos , Reflejo/fisiología , Núcleo Solitario/citología , Núcleo Solitario/efectos de los fármacos , Transmisión Sináptica/efectos de los fármacos , Transmisión Sináptica/fisiología , Aferentes Viscerales/citología , Aferentes Viscerales/efectos de los fármacos , Ácido gamma-Aminobutírico/metabolismoRESUMEN
In BALB/c mice infected with Trichinella spiralis, changes in body temperature (Tb) were observed over 35 days after the infection. T. spiralis infection induced hypothermia two times at 7 and 28 days after infection. The initial decrease persisted for about one week with a peak (37.1 +/- 0.62 degrees C) around 10 days after the infection, while the later phase persisted for at least one week. Both 10 and 35 days after the infection, there were remarkable decreases in Tb. The serum glucose level of infected mice at 10 days was significantly (p < 0.01) decreased compared with that of control mice at the same number of days, while the level in infected mice at 35 days was not decreased. Moreover, the later phase of hypothermia was prevented by the cyclooxygenase inhibitor indomethacin (10 mg/kg i.p.), while the initial phase was not. We conclude that hypothermia was caused by two different mechanisms, involving the effects of hypoglycemia and prostaglandins.