Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.1.7 (acetylcholinesterase)
 28,390 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To monitor the fate of the synaptic vesicle membrane compartment, synaptic vesicles were isolated under varying experimental conditions from blocks of perfused Torpedo electric organ. In accordance with previous results, after low-frequency stimulation (0.1 Hz, 1,800 pulses) of perfused blocks of electric organ, a population of vesicles (VP2 type) can be separated by density gradient centrifugation and chromatography on porous glass beads that is denser and smaller than resting vesicles (VP1 type). By simultaneous application of fluorescein isothiocyanate-dextran as extracellular volume marker and [3H]acetate as precursor of vesicular acetylcholine, and by identifying the vesicular membrane compartment with an antibody against the synaptic vesicle transmembrane glycoprotein SV2, we can show that the membrane compartment of part of the synaptic vesicles becomes recycled during the stimulation period. It then contains both newly synthesized acetylcholine and a sample of extracellular medium. Recycled vesicles have not incorporated the presynaptic plasma membrane marker acetylcholinesterase. Cisternae or vacuoles are presumably not involved in vesicle recycling. After a subsequent period of recovery (18 h), all vesicular membrane compartments behave like VP1 vesicles on subcellular fractionation and still retain both volume markers. Our results imply that on low-frequency stimulation, synaptic vesicles are directly recycled, equilibrating their luminal contents with the extracellular medium and retaining their membrane identity and capability to accumulate acetylcholine.
 ...
PMID:Recycled synaptic vesicles contain vesicle but not plasma membrane marker, newly synthesized acetylcholine, and a sample of extracellular medium. 239 59

Many teleosts actively regulate buoyancy by using a gas-filled swim bladder, which is thought to be under autonomic control. Here we investigated the swim bladder in the zebrafish to determine possible mechanisms of gas-content regulation. Fluorescently labelled phalloidin revealed myocytes that appeared to form a possible sphincter at the junction of the pneumatic duct and esophagus. Myocytes also formed thick bands along the ventral surface of the anterior chamber and bilaterally along the posterior chamber. Thinner layers of myocytes were located elsewhere. Staining of peroxidase within erythrocytes revealed a putative rete and smaller blood vessels in muscle bands and elsewhere. The antibodies zn-12, a general neuronal marker, and SV2, a synaptic vesicle marker labelling presynaptic terminals, revealed widespread innervation of the swim bladder system. Widespread innervation of the swim bladder was also indicated by acetylcholinesterase histochemistry, but choline acetyltransferase-immunoreactive (-IR) somata and fibers were limited to the junction of the pneumatic duct and esophagus. In contrast, varicose tyrosine hydroxylase-IR fibers innervated muscles and blood vessels throughout the system. Neuropeptide Y-IR somata were located near the junction of the duct and esophagus and varicose fibers innervated muscles and vasculature of the posterior chamber and duct. Vasoactive intestinal polypeptide immunoreactivity was abundant throughout the anterior chamber but sparsely distributed elsewhere. Serotonin-IR fibers and varicosities were located only along blood vessels near the junction of the pneumatic duct and posterior chamber. Our results suggest that the zebrafish swim bladder is a complex and richly innervated organ and that buoyancy-regulating effectors may be controlled by multiple populations of autonomic neurons.
 ...
PMID:Structure and autonomic innervation of the swim bladder in the zebrafish (Danio rerio). 1649 79