Radioligands synaptosomes

The interaction of (+)-kavain with receptor site 1 of Na channels, which is the epitope of antagonists like saxitoxin and tetrodotoxin, and its influence on site 2, the binding site of agonists including veratridine, batrachotoxin, and aconitine, were investigated on cerebrocortical synaptosomes by radioligand-binding assays. 

A second phase of the work made use of a radioligand assay for N-type channel binding in the chick brain. Using radiolabelled (o-conotoxin GVIA ((d-CTX), a peptide calcium channel antagonis, we confirmed the diversity of (o-agatoxin in funnel web spider venom and described a new class of toxins (Type III) which have broad specificity for vertebrate high threshold calcium channels. Subsequently, we used potassium stimulated synaptosomal calcium flux to discover toxins that block P-type calcium channels in the mammalian bndn. 

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