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Potassium Movements in Relation to Synaptosomal Morphology
Author(s) -
Csillag András,
Hajós Ferenc
Publication year - 1980
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1980.tb11172.x
Subject(s) - synaptosome , potassium , chemistry , biophysics , membrane , membrane potential , concentration gradient , morphology (biology) , biochemistry , chromatography , biology , organic chemistry , genetics
The uptake of K + by rat cortical synaptosomes was followed using a K + ‐selective membrane electrode. A parallel morphological study was carried out based on the previous description of two different configurations of incubated synaptosomes (S and M configurations). Synaptosomes were able to take up K + against a concentration gradient; the average amount of cation taken up at equilibrium was 42.3 ± 3.1 (7) nmol/mg protein. Following K + uptake the particles displayed a configuration corresponding to that of intact nerve endings in situ (‘M‐configuration’). In conditions where the uptake of K + was inhibited or a net loss was elicited the development of M‐configuration was prevented. Agents which affected both the plasma membrane Na + ‐K + transport system and mitochondrial energy conservation brought about the ‘S‐configuration’ characteristic of unincubated synaptosomes, whereas in conditions where the plasma membrane transport system was preferentially inhibited, transitional forms were found. It was concluded that the S to M transition found in incubated synaptosomes is primarily associated with the inward movement of potassium.