ISSN:
1432-1912
Schlagwort(e):
Synaptic transmission
;
14C-choline
;
Acetylcholine
;
Phosphatidylcholine
;
Urethane anesthesia
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Medizin
Notizen:
Summary Concentrations and specific radioactivities of choline, acetylcholine, phosphorylcholine, lipid choline, and sn-glycero-3-phosphorylcholine after i.v. injection of methyl-14C-choline were measured in the brain of untreated controls and of rats anesthesized with urethane. The specific activity was found to be decreased during deep anesthesia by 40% in acetylcholine, 20–30% in phosphorylcholine, 50–75% in lipid choline, and 30–40% in sn-glycero-3-phosphorylcholine. No significant change was detected in the specific activity of choline. The brain concentration of acetylcholine was increased by 40%, the concentration of sn-glycero-3-phosphorylcholine, however, was diminished by 10% during anesthesia. No change was found in the concentration of the other choline containing compounds investigated. Measuring choline incorporation into 4 subcellular fractions of brain tissue specific activities were found to be decreased by the same percentage, although 2 fractions (nuclei and microsomes) were higher labelled than the 2 other fractions (crude mitochondria with synaptosomes and lysosomes). A correlation between the biochemical and the functional alterations is supported by the dose-effect relationships on both parameters. It is suggested that urethane reduces turnover of lipids and by that mechanism inhibits the exocytotic release of the transmitter from presynaptic nerve endings.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00500888
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