Characterization of alpha-latrotoxin interaction with rat brain synaptosomes and PC12 cells.
alpha-latrotoxin, a polypeptide neurotoxin purified from the venom of the spider Latrodectus mactans tredecimguttatus, induces a massive release of a variety of neurotransmitters from rat brain synaptosomes and a clonal pheochromocytoma cell line (PC12 cells). In both systems secretion of catecholamines is dose- and calcium-dependent. Efflux of catecholamines is coupled with a substantial release of intracellular ATP. Independent of alpha-latrotoxin with PC12 cells is followed by a rapid influx of calcium and sodium ions, the rate being dependent on toxin and calcium concentrations. By reductive methylation it is possible to radioactively label alpha-latrotoxin without appreciable loss of neurotoxicity. A sensitive binding assay in vitro allows the identification of a limited number of specific binding sites in central nervous system synaptic membranes and PC12 cells, for which tritiated alpha-latrotoxin displays nanomolar affinity.
D000310:Adrenal Gland Neoplasms; D000818:Animals; D001180:Arthropod Venoms / Q000494:pharmacology*; D001693:Biological Transport, Active / Q000187:drug effects; D001921:Brain / Q000187:drug effects / Q000502:physiology*; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D007700:Kinetics; D009638:Norepinephrine / Q000378:metabolism; D010673:Pheochromocytoma; D051381:Rats; D013111:Spider Venoms / Q000494:pharmacology*; D013574:Synaptosomes / Q000187:drug effects / Q000502:physiology*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D001180:Arthropod Venoms; D013111:Spider Venoms; D005680:gamma-Aminobutyric Acid; C020763:alpha-latrotoxin; D002118:Calcium; D009638:Norepinephrine