Influence of Vasoactive Substances on the Regulation of Cardiac ATP-Sensitive Potassium Channel Activity
Korean Circulation Journal
;
: 516-525, 2006.
Artículo
en Coreano
| WPRIM
| ID: wpr-183598
ABSTRACT
BACKGROUND AND OBJECTIVES:
It has been known that various vasoactive agents are involved in the regulation of cardiac function through the modification of the K+ channel activities, including the ATP-sensitive K+ channel (KATP). We examined the effects of several vasoactive agents on the cardiac KATP currents in isolated cardiac myocytes. MATERIALS ANDMETHODS:
Ventricular myocytes were isolated from the hearts of ICR mice by enzymatic digestion. The channel currents were recorded by the excised inside-out and cell-attached patch clamp configurations.RESULTS:
In the excised inside-out patches, bradykinin (BRK; 1-10 micrometer) and prostaglandin I2 (PGI; 10-50 micrometer) did not affect the channel activities, whereas the vasodilators increased the attenuated channel activities in the presence of 100 micrometer ATP. BRK and PGI in parallel shifted the dose-response curves of ATP (1-1,000 micrometer), and this inhibited the KATP currents to the right. Endothelin (ET-1; 0.1-1 nM) and leukotriene D4 (LTD; 3-10 micrometer) decreased the channel activities immediately after making the inside-out patches. However, the vasoconstrictors did not affect the attenuated channel activities by ATP. In the cell-attached patches, both BRK and PGI increased the channel activities and these effects were markedly attenuated by glibenclamide (50 micrometer). ET-1 and LTD did not affect the baseline channel activities in the cell-attached patches, but they markedly attenuated the dinitrophenol-induced activities.CONCLUSION:
It was inferred that certain vasoactive substances are involved in the regulation of cardiac KATP channel activities, and that bradykinin and PGI2 enhance the channel activities, and ET-1 and LTD4 inhibit the channel activities.
Texto completo:
Disponible
Índice:
WPRIM (Pacífico Occidental)
Asunto principal:
Potasio
/
Vasoconstrictores
/
Vasodilatadores
/
Bradiquinina
/
Canales de Potasio
/
Adenosina Trifosfato
/
Endotelinas
/
Epoprostenol
/
Gliburida
/
Leucotrieno D4
Tipo de estudio:
Estudio diagnóstico
Límite:
Animales
Idioma:
Coreano
Revista:
Korean Circulation Journal
Año:
2006
Tipo del documento:
Artículo
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