RESUMEN
The effect of regulatory peptide thyrotropin-releasing hormone (TRH) on the structure of the plasma membrane and morphology of rat erythrocytes was studied using a spin probe and scanning electron microscopy. EPR spectra of the spin probe introduced in the intramembrane space demonstrate that TRH at 10(-7) and 10(-3) M induces structural changes in the erythrocyte membrane. Scanning electron microscopy showed that introduction of TRH at 10(-11), 10(-7), and 10(-3) M in the erythrocyte suspension increased the proportion of discocytes as compared to the control. This effect is due to TRH-induced cell transformation in discocytes. The obtained data suggest that TRH affects the membrane structure and the morphology of erythrocytes, changes the functional activity of these cells and, thus, indirectly influences the rate of the oxygen supply to tissue.
Asunto(s)
Eritrocitos/efectos de los fármacos , Hormona Liberadora de Tirotropina/farmacología , Animales , Relación Dosis-Respuesta a Droga , Espectroscopía de Resonancia por Spin del Electrón , Membrana Eritrocítica/efectos de los fármacos , Membrana Eritrocítica/ultraestructura , Eritrocitos/ultraestructura , Microscopía Electrónica de Rastreo , RatasRESUMEN
Scanning electron microscopy revealed changes in erythrocyte morphology induced by the synthetic antioxidant phenozan-1. Phenozan-1 at 10(-7)-10(-5) M acts as an echinocytogen. This effect of the antioxidant is, probably, due to its distribution in the external monolayer of the erythrocyte membrane and associated structural changes.
Asunto(s)
Antioxidantes/farmacología , Membrana Eritrocítica/efectos de los fármacos , Fenilpropionatos/farmacología , Relación Dosis-Respuesta a Droga , Membrana Eritrocítica/ultraestructura , Humanos , Microscopía Electrónica de Rastreo , Propiedades de SuperficieRESUMEN
Using the spin probe technique, the changes in the supramolecular structure of the central nervous system synaptic membranes and of olfactory hair membranes of Rana temporaria induced by low molecular weight organic substances of different chemical nature, were investigated. It was found that the membrane structures under study differ considerably in their sensitivity to chemical stimulation and in temporal kinetics of structural transitions. A correlation between physiological parameters of olfactory perception of the compounds used and the parameters of structural transitions in olfactory hair membranes was established. The interrelationship between the experimental data and chemoreception of odorants and mediators as well as the applicability of these preparations for membrane screening of biologically active substances are discussed.
Asunto(s)
Membranas/ultraestructura , Membranas Sinápticas/ultraestructura , Animales , Encéfalo/ultraestructura , Espectroscopía de Resonancia por Spin del Electrón , Rana temporaria , Marcadores de SpinRESUMEN
The spin probing technique was used to study the interaction of preparations of rat cerebral cortex synaptic membranes with specific antisera. It was found that the fluidity of membrane matrix largely depended on the nature of physiological processes involving synaptic membranes in vivo. The supramolecular structure of synaptic membranes isolated from the brain of trained animals differed from that of controls. Differences in the properties of synaptic membranes were also revealed during their incubation with specific antisera. The data obtained are interpreted in terms of immunochemical theory of memory and training.
Asunto(s)
Corteza Cerebral/ultraestructura , Sueros Inmunes , Fluidez de la Membrana , Membranas Sinápticas/ultraestructura , Animales , Corteza Cerebral/fisiología , Espectroscopía de Resonancia por Spin del Electrón , Aprendizaje , Masculino , Ratas , Marcadores de Spin , Membranas Sinápticas/fisiologíaAsunto(s)
Corteza Cerebral/inmunología , Condicionamiento Clásico/fisiología , Membranas Sinápticas/inmunología , Animales , Especificidad de Anticuerpos , Reacciones Antígeno-Anticuerpo , Corteza Cerebral/fisiología , Corteza Cerebral/ultraestructura , Reacciones Cruzadas , Espectroscopía de Resonancia por Spin del Electrón , Luz , Conformación Molecular , Ratas , Membranas Sinápticas/fisiologíaRESUMEN
By studying fluorescent parameters of ionic and neutral probes the kinetics of complex formation between the molecules of bovine serum albumin (BSA) and unsaturated fatty acids was investigated. The following regularities were observed: 1. Unlike the saturated fatty acids the unsaturated ones changed fluorescent parameters of the probes according to the cooperative mechanism, significantly decreasing the quantum yield values; 2. Temperature dependence of the fluorescence of both probe types in the complexes BSA -- oleic acid and BSA -- linole acid shows some bends at t=30--39 degrees C for which the lipid components is responsible.
Asunto(s)
Ácidos Grasos Insaturados , Albúmina Sérica Bovina , Naftalenosulfonatos de Anilina , Ácidos Araquidónicos , Fluorescencia , Ácidos Linoleicos , Naftalenos , Ácidos Oléicos , Unión Proteica , TemperaturaRESUMEN
Kinetic peculiarities of the sorption of natural limited fatty acids on the molecules of bovine serum albumine (BSA) were studied by investigating fluorescent parameters of ionic (1-anilinonaphtalin-8-sulphonate-ANS) and neutral (N-phenyl-1-naphtylamine-PNA) probes. The following regularities were found: 1. The parameters which characterize the microsurroundings of both probes (quantum yield of fluorescence, the binding constant) did not change significantly during the sorption of the fattyn acids (laurinic, palmitinic and methyl ether of the stearinic acid). An exponential character of BSA fluorescent titration with fatty acids points to a competitive character of the relationship dye -- fatty acid for the binding sites in hydrophobic sacks of BSA. 2. The study of the character of the effect of solution ionic strength on the sorption of fatty acids showed that along with hydrophobic interactions the electrostatic interaction between carboxyl residues of fatty acids and charged protein groups also significantly contributed to this process. 3. Temperature relationship of AMS and PNA fluorescence intensity in the complex BSA -- laurinic acid correlates well with temperature relationship obtained from a pure protein system.