RESUMEN
We performed ultrastructural study of cerebral cortex mitochondria in rats with different tolerance to oxygen deficiency (low resistant and highly resistant specimens). Low resistant rats were characterized by the prevalence of mitochondria with lightened matrix due to the nondense packing of cristae. By contrast, mitochondria of highly resistant animals had the dense packing of cristae. The structure of mitochondria underwent adaptive changes at 14-10% O2 in the inspired air. Under these conditions, structural characteristics of the cerebral cortex in hypoxia-sensitive rats resembled those in resistant animals. The decrease in O2 concentration to 8% was accompanied by ultrastructural signs of mitochondrial damage, which correlated with de-energization of the cell and dysfunction of adaptive signaling systems. Ultrastructural features of cerebral cortex mitochondria in animals with low and high tolerance to acute oxygen deficiency confirm the hypothesis that they are associated with two different "functionaland-metabolic portraits".
Asunto(s)
Adaptación Fisiológica , Mal de Altura/patología , Mitocondrias/ultraestructura , Oxígeno/farmacología , Corteza Prefrontal/ultraestructura , Mal de Altura/fisiopatología , Animales , Animales no Consanguíneos , Modelos Animales de Enfermedad , Microtomía , Mitocondrias/efectos de los fármacos , Mitocondrias/patología , Corteza Prefrontal/efectos de los fármacos , Corteza Prefrontal/patología , Corteza Prefrontal/fisiopatología , Ratas , Técnicas de Cultivo de TejidosRESUMEN
The effect of temperature (range of 4-44 degrees C) upon induced aggregation of platelets from normal subjects was studied. It was shown that temperature dependences of aggregation degree and rate have maxima. A relationship between aggregation agonist kind and some features of the temperature dependence curve of the aggregation parameters is established. It was shown that the limitation of platelet membrane lipids mobility by means of lipids peroxidation leads to the shift of maxima of the temperature dependence curve of platelet aggregation degree and rate. It was concluded that character of aggregation temperature dependence was governed by phase transition in platelet membrane lipids at room temperature.
