Characterization of a new muscarinic toxin from the venom of the Brazilian coral snake Micrurus lemniscatus in rat hippocampus
Life sci. (1973)
; 89(25/26): 931-938, Dec 19, 2011.
Article
en En
| SES-SP, SESSP-IBPROD, SES-SP, SESSP-IBACERVO
| ID: biblio-1064623
Biblioteca responsable:
BR78.1
Ubicación: BR78.1
ABSTRACT
We have isolated a new muscarinic protein (MT-Mlá) from the venom of the Brazilian coral snake Micrurus lemniscatus.The MT-Mlá was able to displace the [3H]QNB binding in the hippocampus of rats. The bindingcurve in competition experiments with MT-Mlá was indicative of two types of [3H]QNB-binding site with pKivalues of 9.08±0.67 and 6.17±0.19, n=4, suggesting that various muscarinic acetylcholine receptor(mAChR) subtypes may be the target proteins of MT-Mlá. The MT-Mlá and the M1 antagonist pirenzepinecaused a dose-dependent block on total [3H]inositol phosphate accumulation induced by carbachol. TheIC50 values for MT-Mlá and pirenzepine were, respectively, 33.1 and 2.26 nM. Taken together, these studies indicate that the MT-Mlá has antagonist effect on mAChRs in rat hippocampus.The results of the present study show, for the first time, that mAChRs function is drasticallyaffected by MT-Mlá since it not only has affinity for mAChRs but also has the ability to inhibit mAChRs.
Palabras clave
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Colección:
06-national
/
BR
Base de datos:
SES-SP
/
SESSP-IBACERVO
/
SESSP-IBPROD
Asunto principal:
Elapidae
/
Venenos Elapídicos
Límite:
Animals
País/Región como asunto:
America do sul
/
Brasil
Idioma:
En
Revista:
Life sci. (1973)
Año:
2011
Tipo del documento:
Article