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https://hdl.handle.net/10316/10170
Title: | Interacção de catiões com membranas do músculo e do cérebro | Authors: | Carvalho, Caetana Angélica Ermitão Monteiro de | Orientador: | Carvalho, Arsélio Pato de Madeira, Vítor Manuel Calado |
Keywords: | Biologia celular | Issue Date: | 29-Feb-1980 | Citation: | CARVALHO, Caetana Angélica Ermitão Monteiro de - Interacção de catiões com membranas do músculo e do cérebro. Coimbra, 1979. | Abstract: | The Ca2+ stimulated ATPase activity of sarcoplasmic reticulum ( SR ) is activated after a short period of preincubation at temperatures between 40 and 450C, but for temperatures higher than 480C pronounced denaturation is observed. Heat denaturation is decreased if Mg2+ or K+ are present which is attributed to stabilization by cations of the ATPase Ca2+ transport coupled to the ATPase activity in SR was followed by using the chlorotetracycline ( CTC ) fluorescense technique, and it is concluded that the Ca2+ accumulated in the presence of ATP is mostly bound to the membranes. The fluorescence of CTC was also utilized to follow the interaction of Ca2+ with brain membranes, and the technique was found to be useful to monitor the binding and release of Ca2+ in synaptosomes and other brain membrane fractions. The passive permeability of synaptosomes to electrolytes and non-electrolytes is temperature dependent. Furthermore, the fluxes of Ca2+, Sr2+ and Mg2+ were studied and the results suggest that the efflux of Ca2+ in synaptosomes is induced selectively by Na+, which is a major mechanism responsible for the regulation of Ca2+ in the nerve cell. | Description: | Tese de doutoramento em Biologia Físico-Química apresentada à Fac. de Ciências e Tecnologia de Coimbra | URI: | https://hdl.handle.net/10316/10170 | Rights: | embargoedAccess |
Appears in Collections: | FCTUC Ciências da Vida - Teses de Doutoramento |
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