The effect of increasing [K+]0 on 3H-glycogen levels was examined in mouse cerebral cortical slices. K+ stimulates in a time- and concentration-dependent manner the hydrolysis of 3H-glycogen. Over 70% of the maximal effect is reached within 30 sec and the EC50 for the glycogenolytic action of K+ is 11 mM. Significant 3H-glycogen hydrolysis occurs at 5-12 mM [K+]0, concentrations reached by the ion in the extracellular space during neuronal activity. The K+-evoked glycogenolysis is Ca2+-dependent, and is inhibited by Ca2+-channel blockers such as Ni2+ and Mn2+, but not by Cd2+, nifedipine, and omega-conotoxin. Furthermore, the effect of K+ is not enhanced by the Ca2+-channel agonist Bay K 8644. This type of pharmacological profile suggests that the activation of voltage-sensitive Ca2+ channels of the T subtype mediates the glycogenolytic action of K+. This set of observations suggests that K+ released in the extracellular space by active neurons may promote the mobilization of energy substrates and therefore play a role in the coupling between neuronal activity and energy metabolism.
K+ at concentrations reached in the extracellular space during neuronal activity promotes a Ca2+-dependent glycogen hydrolysis in mouse cerebral cortex / Hof, Pr; Pascale, Esterina; Magistretti, Pj. - In: THE JOURNAL OF NEUROSCIENCE. - ISSN 0270-6474. - STAMPA. - 8(1988).
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Titolo: | K+ at concentrations reached in the extracellular space during neuronal activity promotes a Ca2+-dependent glycogen hydrolysis in mouse cerebral cortex. | |
Autori: | ||
Data di pubblicazione: | 1988 | |
Rivista: | ||
Citazione: | K+ at concentrations reached in the extracellular space during neuronal activity promotes a Ca2+-dependent glycogen hydrolysis in mouse cerebral cortex / Hof, Pr; Pascale, Esterina; Magistretti, Pj. - In: THE JOURNAL OF NEUROSCIENCE. - ISSN 0270-6474. - STAMPA. - 8(1988). | |
Handle: | http://hdl.handle.net/11573/431410 | |
Appartiene alla tipologia: | 01a Articolo in rivista |