Uptake and metabolism of choline in the organotypic culture of newborn mouse cerebellum.
The uptake and metabolism of [methyl-14C]choline in the organotypic culture of newborn mouse cerebellum was examined. Explants of 8 day in vitro (8 DIV) were incubated for 48 h under standard conditions with 21.0 microM [14C]choline at 35 degrees C. During the first hour of incubation, most of the [14C]choline incorporated was transferred to phosphocholine. The amount of [14C]phosphocholine increased gradually at the initial rate of 0.95 +/- 0.17 nmol/mg protein/h and saturated after 7 h (4.31 +/- 1.30 nmol/mg protein). The synthesis of [14C]phospholipids was observed after a distinct time lag. About 96% of the radioactivity in the lipids was incorporated into phosphatidylcholine. The amount of phosphatidylcholine increased linearly up to 48 h of incubation: 11.9 +/- 2.10 nmol/mg protein at 24 h and 21.9 +/- 2.43 nmol/mg protein at 48 h. From double-label studies it was found that phosphocholine was a precursor of phosphatidylcholine. The content of [14C]choline within explants remained nearly constant through the incubation period. Acetylcholine synthesis in mouse cerebellum culture was relatively low, and the content remained constant through the incubation period (0.006 +/- 0.003 nmol/mg protein). Activities of acetylcholine synthesis of cerebral and cerebellar homogenates were compared. Phosphatidylcholine synthesized in mouse cerebellum culture separated into two spots on thin layer chromatograph using silica gel G plates. Gas chromatographs suggested that the separation depends on the difference in fatty acid composition.
D000109:Acetylcholine / Q000096:biosynthesis; D000375:Aging; D000818:Animals; D000831:Animals, Newborn; D001692:Biological Transport; D001921:Brain / Q000254:growth & development / Q000378:metabolism; D002250:Carbon Radioisotopes; D002531:Cerebellum / Q000378:metabolism*; D002794:Choline / Q000378:metabolism*; D007700:Kinetics; D051379:Mice; D009924:Organ Culture Techniques; D010743:Phospholipids / Q000096:biosynthesis
D002250:Carbon Radioisotopes; D010743:Phospholipids; D002794:Choline; D000109:Acetylcholine