Rat liver was fractionated essentially as described by Hogeboom, Schneider, and Pallade (2). The liver was homogenized in 0.88 M sucrose (1 gm. of liver to 10 ml.) in the cold and centrifuged in 25 ml. Lustroid tubes in a 32” angle centrifuge (Custom Scientific Instruments, Inc.) in a cold room kept at 5”. The homogenate was separated into nuclear, mitochondrial, and supernatant fractions. The ...

We have found that mutant acetylcholine receptor channels (AChRs) that cause slow-channel congenital myasthenic syndromes are activated by serum and that the high frequency of openings in serum is reduced by treatment with choline oxidase. Thus, slow-channel congenital myasthenic syndrome AChRs at the neuromuscular junction are likely to be activated both by steady exposure to serum choline and...

When type II pneumonocytes from adult rats were maintained in a medium that lacked choline, the incorporation of ['4C]glycerol into phosphatidylcholine was not greatly diminished during the period that the cells displayed characteristics of type II pneumonocytes. Cells that were maintained in choline-free medium that contained choline oxidase and catalase, however, became depleted of choline an...

Certain general functions of vitamin Blz and folic acid in intermediary metabolism are now well recognized. For example, folic acid appears to be involved in purine and formate metabolism and vitamin Blz in the utilization of methyl groups. However, while there have been several reports concerning the influence in viva and in vitro of folic acid and its antagonist, aminopterin, on specific enzy...