Distribution and turnover rate of acetylcholine receptors throughout the junction folds at a vertebrate neuromuscular junction
| Autor: | M M Salpeter, R Harris |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 1983 |
| Předmět: |
Neuromuscular Junction
Biology Neuromuscular junction law.invention Mice law biology.animal medicine Distribution (pharmacology) Animals Receptors Cholinergic Tissue Distribution Receptor Acetylcholine receptor Vertebrate Cell Biology Anatomy Articles Bungarotoxins Microscopy Electron medicine.anatomical_structure Turnover Biophysics Cholinergic Autoradiography Female Electron microscope |
| Zdroj: | The Journal of Cell Biology |
| ISSN: | 1540-8140 0021-9525 |
| Popis: | The distribution and turnover rate of acetylcholine receptors labeled with 125I-alpha-bungarotoxin were examined in innervated mouse sternomastoid muscle by electron microscope autoradiography using the "mask" analysis procedure. We compared the total population of receptors with receptors newly inserted at the junction 2 d after inactivation with nonradioactive alpha-bungarotoxin, both at the top (thickened) region of the postjunctional folds (pjm) and the nonthickened bottom folds. We found that the receptor site density was approximately 10 times greater on the thickened pjm than on the nonthickened bottom folds for both total and newly inserted receptors. This ratio does not change significantly during a 6-d period after labeling the new receptors. Furthermore, calculated values for turnover time of receptors show that both total and newly inserted receptors at both regions of the junctional folds have half-lives for degradation within the range given in the literature for slow junctional receptors. These data exclude a simple migration model whereby receptors are preferentially inserted in the nonthickened region of the junctional folds and then migrate into the thickened membrane at a rate equal to the turnover rate of the receptors. |
| Databáze: | OpenAIRE |
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