Passive uptake of acetylcholine and other organic cations by synaptic vesicles from Torpedo electric organ

Biochemistry ◽  
1980 ◽  
Vol 19 (18) ◽  
pp. 4373-4379 ◽  
Author(s):  
Richard S. Carpenter ◽  
Robert Koenigsberger ◽  
Stanley M. Parsons
Keyword(s):  
Synaptic Vesicles ◽  
Electric Organ ◽  
Organic Cations ◽  
Torpedo Electric Organ

Kinetics of cation-induced aggregation of Torpedo electric organ synaptic vesicles

1979 ◽  
Vol 557 (2) ◽  
pp. 340-353 ◽  
Author(s):  
Duncan H. Haynes ◽  
Jeffry Lansman ◽  
Anne L. Cahill ◽  
Stephen J. Morris
Keyword(s):  
Synaptic Vesicles ◽  
Electric Organ ◽  
Torpedo Electric Organ ◽  
Induced Aggregation ◽  
Kinetics Of

scholarly journals The heterogeneity of bound acetylcholine and synaptic vesicles

1972 ◽  
Vol 129 (5) ◽  
pp. 1049-1061 ◽  
Author(s):  
R. M. Marchbanks ◽  
M. Israël
Keyword(s):  
Surface Layer ◽  
Synaptic Vesicles ◽  
Osmotic Shock ◽  
Gel Filtration ◽  
Specific Radioactivity ◽  
Electric Organ ◽  
Reciprocal Relationship ◽  
The Other ◽  
Theoretical Treatment ◽  
Torpedo Electric Organ

Synaptic vesicles containing radioactive acetylcholine have been isolated from slices of Torpedo electric organ incubated with radioactive choline. The recently synthesized radioactive acetylcholine is preferentially removed from the vesicles by iso-osmotic gel filtration. There is therefore a small compartment of loosely bound recently synthesized acetylcholine within the monodisperse vesicle fraction. The specific radioactivity of this compartment correlates most closely with the ‘free’ acetylcholine of electric organ that is lost when the tissue is homogenized. Membrane-associated vesicles did not contain any particular enrichment of this compartment. On standing at 6°C the loosely bound compartment stabilizes so that it survives iso-osmotic filtration. A study of this phenomenon revealed that it was proportional to the extent of the loss of tightly bound acetylcholine from the vesicles. Incubation with Ca2+, at pH5.5, or partial hypo-osmotic shock, caused losses of tightly bound acetylcholine and proportional increases in the stabilization of loosely bound acetylcholine of vesicles. Incubation at 20°C caused less loss of tightly bound, and less stabilization of loosely bound, acetylcholine. A theoretical treatment of these exchanges also shows that the random factors promoting loss of tightly bound acetylcholine are statistically correlated with those which cause stabilization of loosely bound acetylcholine. The reciprocal relationship between the exchanges is inconsistent with there being two distinct populations of vesicles, one containing recently synthesized, loosely bound acetylcholine and the other containing tightly bound acetylcholine. It is proposed that all the vesicles contain a core of tightly bound acetylcholine and a surface layer of loosely bound acetylcholine. The origin of the extravesicular acetylcholine and also of the acetylcholine released on stimulation is discussed in the light of these results.

Proton gradient linkage to active uptake of [3H]acetylcholine by Torpedo electric organ synaptic vesicles

Biochemistry ◽  
1982 ◽  
Vol 21 (13) ◽  
pp. 3037-3043 ◽  
Author(s):  
D. C. Anderson ◽  
Steven C. King ◽  
Stanley M. Parsons
Keyword(s):  
Synaptic Vesicles ◽  
Electric Organ ◽  
Proton Gradient ◽  
Active Uptake ◽  
Torpedo Electric Organ

Ganglioside Composition of Synaptic Vesicles from Torpedo Electric Organ

1988 ◽  
Vol 51 (5) ◽  
pp. 1465-1469 ◽  
Author(s):  
Robert W. Ledeen ◽  
Stanley M. Parsons ◽  
Marie F. Diebler ◽  
Michele Sbaschnig-Agler ◽  
S. Lazereg
Keyword(s):  
Synaptic Vesicles ◽  
Electric Organ ◽  
Torpedo Electric Organ ◽  
Ganglioside Composition

scholarly journals Isolation of pure cholinergic nerve endings from Torpedo electric organ. Evaluation of their metabolic properties.

1977 ◽  
Vol 75 (1) ◽  
pp. 43-55 ◽  
Author(s):  
N Morel ◽  
M Israel ◽  
R Manaranche ◽  
P Mastour-Frachon
Keyword(s):  
Synaptic Vesicles ◽  
Morphological Analysis ◽  
Electric Organ ◽  
Nerve Endings ◽  
Cholinergic Nerve ◽  
Membrane Attachment ◽  
Biochemical Measurements ◽  
Torpedo Electric Organ ◽  
Metabolic Properties

Pure cholinergic nerve endings (synaptosomes) were isolated from the electric organ of Torpedo by a rapid procedure. These synaptosomes are approximately 3 micron in diameter. They contain an occasional mitochondrion, numerous synaptic vesicles, and sometimes an active zone is observed. No postynaptic membrane attachment is found. This nerve ending fraction is extremely pure as shown by morphological controls and biochemical data. It is rich in choline acetyltransferase (450 nmol/h per mg protein) and acetylcholine (ACh) (130 nmol/mg protein). The isolated endings retain their cytoplasmic components and they synthesize ACh and are stable in vitro for several hours, as shown by biochemical measurements and morphological analysis.

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