Asunto(s)
Remoción de Dispositivos/métodos , Cuerpos Extraños/cirugía , Gastroscopía/métodos , Páncreas/cirugía , Stents , Enfermedad Crónica , Falla de Equipo , Femenino , Migración de Cuerpo Extraño/cirugía , Gastroscopía/instrumentación , Humanos , Persona de Mediana Edad , Conductos Pancreáticos , Pancreatitis Crónica/terapiaRESUMEN
Sodium/potassium-activated adenosine triphosphatase (Na+/K+-ATPase) activity in the kidney and brain is high, and is regulated by catecholamines. Na+/K+-ATPase activity is also high in the basolateral infoldings of the strial marginal cells, where it aids in maintaining the characteristic electrolyte composition of the endolymph. To clarify the involvement of humoral control in strial function, particularly the role of catecholamines, the K+-dependent p-nitrophenylphosphatase (K+-NPPase) activity of strial marginal cells was investigated in guinea pigs using a cerium-based cytochemical method. The effects of reserpine, serotonin (5-HT), norepinephrine (NE), epinephrine (EP), both alone and in combination, were studied. High doses of reserpine cause depletion of sympathetic substances. Strial K+-NPPase activity was decreased after reserpine or dopamine treatment, and was increased after 5-HT, NE, and EP treatment. After reserpinization, repeated treatment with 5-HT, NE, or EP led to detectable strial enzyme activity. Thus, exogenous 5-HT, NE, and EP were able to restore strial K+-NPPase activity in the reserpine-treated animals. These results suggested that biogenic amines regulate strial K+-NPPase activity. Thus, the function of the stria vascularis may be regulated by the opposing actions of these catecholamines, and 5-HT.
Asunto(s)
Catecolaminas/farmacología , Cóclea/enzimología , ATPasa Intercambiadora de Sodio-Potasio/metabolismo , 4-Nitrofenilfosfatasa/metabolismo , Animales , Cóclea/citología , Cóclea/efectos de los fármacos , CobayasRESUMEN
Peripheral nerve injury induces changes in gene expressions of a variety of neuroactive substances in cell somata, which may have roles in the adaptive response to the injury, neuronal survival, growth and regeneration. In this study, we designed a rat model of ischemic peripheral facial paralysis with a selective embolization technique, and observed mRNA expression of calcitonin gene-related peptide (CGRP), c-jun, and growth associated protein (GAP)-43 in facial nerve nuclei using in situ hybridization histochemistry. The rats were demonstrated to have a transient facial paralysis consistently, and thus this method was regarded as a model of minor peripheral nerve injury. The mRNA of CGRP, c-jun and GAP-43 showed a distinct pattern of induction and time course of increase after the ischemic nerve injury. The results suggest that the small injury to the peripheral nerve was able to induce changes in mRNA expression in the cell body of motoneurons. We also investigated the protective effect of superoxide dismutase (SOD), which is a free radical-scavenging enzyme involved in cellular antioxidant defenses. The SOD treatment clearly alleviated the behavioral impairment and decreased the CGRP mRNA expression at 3rd day after injury. These data suggest that a free radical generated by the ischemia may be partially responsible for ischemic nerve damage and the change in gene expression in motoneurons.
Asunto(s)
Nervio Facial/metabolismo , Parálisis Facial/metabolismo , Depuradores de Radicales Libres/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Superóxido Dismutasa/farmacología , Animales , Axotomía , Péptido Relacionado con Gen de Calcitonina/genética , Péptido Relacionado con Gen de Calcitonina/metabolismo , Modelos Animales de Enfermedad , Embolia , Nervio Facial/irrigación sanguínea , Nervio Facial/patología , Parálisis Facial/tratamiento farmacológico , Proteína GAP-43/genética , Proteína GAP-43/metabolismo , Hibridación in Situ , Isquemia , Masculino , Puente/metabolismo , Puente/patología , Proteínas Proto-Oncogénicas c-jun/genética , Proteínas Proto-Oncogénicas c-jun/metabolismo , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Recuperación de la Función , Reproducibilidad de los Resultados , Hueso Temporal/irrigación sanguínea , Hueso Temporal/inervación , Hueso Temporal/patología , Resultado del TratamientoRESUMEN
Dopamine is often used clinically for the treatment of patients with shock. In a previous study, the Na-KATPase (K-NPPase) activity of strial marginal cells was inhibited after the repeated in vivo administration of dopamine hydrochloride. In the present study, the K-NPPase activity of strial marginal cells was determined using a cerium-based cytochemistry after an in vitro incubation with dopamine. The enzyme reaction product was found in untreated normal strial marginal cells, but it was almost completely undetectable after an in vitro treatment with 10 mM dopamine. This finding suggested that dopamine directly inhibited the Na-KATPase activity of strial marginal cells, and that these cells might have a dopamine receptor.
