A new type of transmitter release at the neuromuscular junction
A new type of transmitter release at the neuromuscular junction
复制标题
神经肌肉接头释放新型递质
DOI：
10.1016/0306-4522(83)90041-6
复制
发表时间：
1983
期刊：
影响因子：
3.3
通讯作者：
J. Molgó
中科院分区：
文献类型：
--
作者：
S. Thesleff;J. Molgó
对小鼠骨骼肌自发微型终板电位(MEPPs)的研究表明，在肉毒杆菌中毒、神经末梢再生或药物4-氨基喹啉存在的情况下，两种类型的乙酰胆碱释放对MEPPs起作用。除了与神经冲动诱发的终板电位的量子分量相对应的MEPP外，还发生了第二种类型的乙酰胆碱释放。后一种类型的发射机释放导致MEPP的峰值时间更长，并且经常比正常幅度更大。它不受神经末梢去极化和跨膜钙离子流量的影响。MEPP频率与温度的关系Q10约为12，而正常MEPP的Q10为2-3。在肉毒杆菌中毒的肌肉中，这种分泌型递质释放占主导地位，仅存在于神经刺激无法释放递质的肌肉中。在正常肌肉中，这种释放是由4-氨基喹啉引起的，这可能导致高达45%的自发MEPP是这种类型的。这表明，所描述的乙酰胆碱的自发分泌具有诱导和神经营养功能。
Examination of spontaneous miniature endplate potentials (MEPPs) in murine skeletal muscle has revealed that in conditions such as botulinum poisoning, during nerve terminal regeneration or in the presence of the drug 4-aminoquinoline, two types of acetylcholine release are responsible for the MEPPs. In addition to the MEPPs which correspond to the quantal component of a nerve impulse-evoked end-plate potential a second type of acetylcholine release occurs. The latter type of transmitter release gives rise to MEPPs with a more prolonged time-to-peak and frequently a larger than normal amplitude. It is unaffected by nerve terminal depolarization and transmembrane Ca2+fluxes. The relationship between MEPP frequency and temperature has a Q10of about 12 compared to 2–3 for normal MEPPs. In botulinum-poisoned muscles this secretory type of transmitter release dominates, being exclusively present in muscles where nerve stimulation fails to release transmitter. In normal muscle such a release is induced by 4-aminoquinoline which may cause up to 45% of all the spontaneous MEPPs to be of that kind. It is suggested that the described spontaneous secretion of acetylcholine serves an inductory and neurotrophic function.