Species selective resistance of cardiac muscle voltage gated sodium channels: characterization of brevetoxin and ciguatoxin binding sites in rats and fish.
Toxicon
; 48(6): 702-12, 2006 Nov.
Article
en En
| MEDLINE
| ID: mdl-16973200
ABSTRACT
Brevetoxins (PbTxs) and ciguatoxins (CTXs) are two suites of dinoflagellate derived marine polyether neurotoxins that target the voltage gated sodium channel (VGSC). PbTxs are commonly responsible for massive fish kills and unusual mortalities in marine mammals. CTXs, more often noted for human intoxication, are suspected causes of fish and marine mammal intoxication, although this has never been reported in the field. VGSCs, present in the membrane of all excitable cells including those found in skeletal muscle, nervous and heart tissues, are found as isoforms with differential expression within species and tissues. To investigate the tissue and species susceptibility to these biotoxins, we determined the relative affinity of PbTx-2 and -3 and P-CTX-1 to native VGSCs in the brain, heart, and skeletal muscle of rat and the marine teleost fish Centropristis striata by competitive binding in the presence of [(3)H]PbTx-3. No differences between rat and fish were observed in the binding of PbTxs and CTX to either brain or skeletal muscle. However, [(3)H]PbTx-3 showed substantial lower affinity to rat heart tissue while in the fish it bound with the same affinity to heart than to brain or skeletal muscle. These new insights into PbTxs and CTXs binding in fish and mammalian excitable tissues indicate a species related resistance of heart VGSC in the rat; yet, with comparable sensitivity between the species for brain and skeletal muscle.
Buscar en Google
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Lubina
/
Canales de Sodio
/
Ciguatoxinas
/
Proteínas de Peces
/
Miocitos Cardíacos
/
Oxocinas
/
Toxinas Marinas
/
Neurotoxinas
Límite:
Animals
Idioma:
En
Revista:
Toxicon
Año:
2006
Tipo del documento:
Article
País de afiliación:
Estados Unidos