Ascorbic acid, an endogenous factor required for acetylcholine release from the synaptic vesicles.
The ACh-releasing factor, which is required for ACh release in presence of 2 mM ATP, 2 mM Mg and 10(-5) M Ca from isolated synaptic vesicles, was purified from the synaptosomal cytoplasm of rat brain by Sephadex G-15, DEAE-Sephadex, Sephadex G-10 and AG50W-2X column chromatographies and identified as ascorbic acid. A low concentration of L-ascorbic acid (5 x 10(-6) M) produced a release of ACh from the vesicles in the presence of ATP, MgCl2 and CaCl2, as did synaptosomal cytoplasm. This release of ACh induced by L-ascorbic acid was found to be dissociable from formation of lipid peroxide. These findings are discussed in relation to the physiological role of L-ascorbic acid in the brain.
D000109:Acetylcholine / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000502:physiology; D000818:Animals; D001205:Ascorbic Acid / Q000302:isolation & purification / Q000502:physiology*; D002118:Calcium / Q000502:physiology; D002614:Chelating Agents / Q000494:pharmacology; D002845:Chromatography; D066298:In Vitro Techniques; D008054:Lipid Peroxides / Q000096:biosynthesis; D008274:Magnesium / Q000502:physiology; D051381:Rats; D013056:Spectrophotometry, Ultraviolet; D013572:Synaptic Vesicles / Q000378:metabolism*
D002614:Chelating Agents; D008054:Lipid Peroxides; D000255:Adenosine Triphosphate; D008274:Magnesium; D000109:Acetylcholine; D001205:Ascorbic Acid; D002118:Calcium