TY - JOUR T1 - High affinity choline uptake and calcium-dependent acetylcholine release in proteoliposomes derived from rat cortical synaptosomes JF - The Journal of Neuroscience JO - J. Neurosci. SP - 987 LP - 994 DO - 10.1523/JNEUROSCI.03-05-00987.1983 VL - 3 IS - 5 AU - EM Meyer AU - JR Cooper Y1 - 1983/05/01 UR - http://www.jneurosci.org/content/3/5/987.abstract N2 - Proteoliposomes were prepared from rat cortical synaptic plasma membranes that retained high and low affinity choline transport. High affinity transport was inhibited by hemicholinium-3 in a competitive manner and was apparently dependent on membrane potential or ion gradients. Proteoliposomes supplemented with an acetylcholine- generating system were able to synthesize [3H]ACh de novo from [3H]choline taken up by high or low affinity transport; however, we were able to specifically load proteoliposomes derived from cholinergic membranes by using a low choline concentration. [3H]ACh, but not [3H]choline, was subsequently released in a calcium-dependent manner by K+ depolarization. This preparation offers a simplified membrane system for studying functional high affinity choline transport and nonvesicular ACh release. ER -