Regulation of Coronary Arterial Large Conductance Ca2+-Activated K+ Channel Protein Expression and Function by n-3 Polyunsaturated Fatty Acids in Diabetic Rats.
J Vasc Res
; 54(6): 329-343, 2017.
Article
em En
| MEDLINE
| ID: mdl-29040972
ABSTRACT
AIM:
The objective of this study was to examine the effects of n-3 polyunsaturated fatty acids (n-3 PUFAs) on coronary arterial large conductance Ca2+-activated K+ (BK) channel function in coronary smooth muscle cells (SMCs) of streptozotocin-induced diabetic rats.METHODS:
The effects of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on coronary BK channel open probabilities were determined using the patch clamp technique. The mRNA and protein expressions of BK channel subunits were measured using qRT-PCR and Western blots. The coronary artery tension and coronary SMC Ca2+ concentrations were measured using a myograph system and fluorescence Ca2+ indicator.RESULTS:
Compared to nondiabetic control rats, the BK channel function was impaired with a reduced response to EPA and DHA in freshly isolated SMCs of diabetic rats. Oral administration of n-3 PUFAs had no effects on protein expressions of BK channel subunits in nondiabetic rats, but significantly enhanced those of BK-ß1 in diabetic rats without altering BK-α protein levels. Moreover, coronary ring tension induced by iberiotoxin (a specific BK channel blocker) was increased and cytosolic Ca2+ concentrations in coronary SMCs were decreased in diabetic rats, but no changes were found in nondiabetic rats.CONCLUSIONS:
n-3 PUFAs protect the coronary BK channel function and coronary vasoreactivity in diabetic rats as a result of not only increasing BK-ß1 protein expressions, but also decreasing coronary artery tension and coronary smooth muscle cytosolic Ca2+ concentrations.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Vasoconstrição
/
Doença da Artéria Coronariana
/
Ácido Eicosapentaenoico
/
Ácidos Docosa-Hexaenoicos
/
Miócitos de Músculo Liso
/
Diabetes Mellitus Experimental
/
Diabetes Mellitus Tipo 1
/
Angiopatias Diabéticas
/
Subunidades beta do Canal de Potássio Ativado por Cálcio de Condutância Alta
/
Músculo Liso Vascular
Idioma:
En
Revista:
J Vasc Res
Assunto da revista:
ANGIOLOGIA
Ano de publicação:
2017
Tipo de documento:
Article
País de afiliação:
China