Thursday, July 24, 2014

 

 



Soy un nuevo usuario

Olvidé mi contraseña

Entrada usuarios

Lógica Matemáticas Astronomía y Astrofísica Física Química Ciencias de la Vida
Ciencias de la Tierra y Espacio Ciencias Agrarias Ciencias Médicas Ciencias Tecnológicas Antropología Demografía
Ciencias Económicas Geografía Historia Ciencias Jurídicas y Derecho Lingüística Pedagogía
Ciencia Política Psicología Artes y Letras Sociología Ética Filosofía


Pacemaker activity and ionic currents in mouse atrioventricular node cells

1) La descarga del recurso depende de la página de origen
2) Para poder descargar el recurso, es necesario ser usuario
    registrado en Universia

  Descargar recurso

Detalles del recurso

Pertenece a: PubMed Central (PMC3 - NLM DTD)  

Descripción: It is well established that pacemaker activity of the sino-atrial node (SAN) initiates the heartbeat. However, the atrioventricular node (AVN) can generate viable pacemaker activity in case of SAN failure, but we have limited knowledge of the ionic bases of AVN automaticity. We characterized pacemaker activity and ionic currents in automatic myocytes of the mouse AVN. Pacemaking of AVN cells (AVNCs) was lower than that of SAN pacemaker cells (SANCs), both in control conditions and upon perfusion of isoproterenol (ISO). Block of INa by tetrodotoxin (TTX) or of ICa,L by isradipine abolished AVNCs pacemaker activity. TTX-resistant (INar) and TTX-sensitive (INas) Na+ currents were recorded in mouse AVNCs, as well as T-(ICa,T) and L-type (ICa,L) Ca2+ currents. ICa,L density was lower than in SANCs (51%). The density of the hyperpolarization-activated current, (If) and that of the fast component of the delayed rectifier current (IKr) were, respectively, lower (52%) and higher (53%) in AVNCs than in SANCs. Pharmacological inhibition of If by 3 µM ZD-7228 reduced pacemaker activity by 16%, suggesting a relevant role for If in AVNCs automaticity. Some AVNCs expressed also moderate densities of the transient outward K+ current (Ito). In contrast, no detectable slow component of the delayed rectifier current (IKs) could be recorded in AVNCs. The lower densities of If and ICa,L, as well as higher expression of IKr in AVNCs than in SANCs may contribute to the intrinsically slower AVNCs pacemaking than that of SANCs.

Autor(es): Marger, Laurine -  Mesirca, Pietro -  Alig, Jacqueline -  Torrente, Angelo -  Dubel, Stefan -  Engeland, Birgit -  Kanani, Sandra -  Fontanaud, Pierre -  Striessnig, Jörg -  Shin, Hee -  Sup -  Isbrandt, Dirk -  Ehmke, Heimo -  Nargeot, Joël -  Mangoni, Matteo E - 

Id.: 55236549

Idioma: English  - 

Versión: 1.0

Estado: Final

Palabras claveResearch Paper - 

Tipo de recurso: Text  - 

Tipo de Interactividad: Expositivo

Nivel de Interactividad: muy bajo

Audiencia: Estudiante  -  Profesor  -  Autor  - 

Estructura: Atomic

Coste: no

Copyright: sí

Requerimientos técnicos:  Browser: Any - 

Fecha de contribución: 02-may-2012

Contacto:

Localización:


Otros recursos de la misma colección

  1. PKA-independent activation of If by cAMP in mouse sinoatrial myocytes Hyperpolarization-activated, cyclic nucleotide-sensitive (HCN4) channels produce the “funny current,...
  2. Engineered Kir6.2 mutations that correct the trafficking defect of KATP channels caused by specific SUR1 mutations KATP channels consisting of Kir6.2 and SUR1 couple cell metabolism to membrane excitability and regu...
  3. Cholesterol sensitivity of KIR2.1 depends on functional inter-links between the N and C termini In recent years, cholesterol has been emerging as a major regulator of ion channel function. We have...
  4. Acid sensitive background potassium channels K2P3.1 and K2P9.1 undergo rapid dynamin-dependent endocytosis Acid-sensitive, two-pore domain potassium channels, K2P3.1 and K2P9.1, are implicated in cardiac and...
  5. Cholesterol regulates HERG K+ channel activation by increasing phospholipase C β1 expression Human ether-a-go-go-related gene (HERG) K+ channel underlies the rapidly activating delayed rectifie...

Valoración de los usuarios

No hay ninguna valoración para este recurso.Sea el primero en valorar este recurso.
 

Busque un recurso