Linked Life Data

7620623

Source:http://linkedlifedata.com/resource/pubmed/id/7620623

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1995-8-30
pubmed:abstractText
In this report we show that alpha-latrotoxin from black widow spider venom is a potent activator of neurotransmitter release in synaptosomes from the Torpedo electric organ. Binding of the purified toxin (5 nM) to the synaptosomal fraction occurs already at 4 degrees C and is dependent on the presence of divalent ions. However, neurotransmitter release commences only after temperature elevation (22 degrees C) and is completed within 2 min. The effect of alpha-latrotoxin on release is achieved at 1 nM and is already saturated at 5 nM. The release is stimulated by the presence of Ca2+ ions. Activation of release by alpha-latrotoxin is accompanied by morphological changes in electric organ synaptosomes. The synaptosomes swell, resulting in a 55% increase in section area. Moreover, the number of synaptic vesicles per unit area decreases about three-fold, and rows of docked synaptic vesicles are rarely detected as opposed to control synaptosomes. These morphological changes indicate that the massive release is mainly due to synaptic vesicle fusion. alpha-Latrotoxin binding sites are highly concentrated in the innervated face of the electrocytes. Immunoelectron microscopy on electric organ sections reveals alpha-latrotoxin binding sites over the entire plasma membrane at release sites and facing Schwann cells surrounding Torpedo nerve terminals. Surprisingly, a high concentration of binding sites is also found at structures surrounding branching unmyelinated axons. This staining is in close proximity to Schwann cell envelopes and to the basal lamina around axonal tips. The mode of action of alpha-latrotoxin in view of the localization of its binding sites is discussed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0953-816X
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
7
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
742-52
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
alpha-latrotoxin is a potent inducer of neurotransmitter release in Torpedo electric organ--functional and morphological characterization.
pubmed:affiliation
Department of Biological Chemistry, Alexander Silberman Institute of Life Sciences, Jerusalem, Israel.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't