Changes of open probability of large conductance Ca(2+)-activated K(+) channels in diabetic coronary smooth muscle cells of rats / 中华心血管病杂志
Chinese Journal of Cardiology
; (12): 770-774, 2012.
Article
em Zh
| WPRIM
| ID: wpr-326423
Biblioteca responsável:
WPRO
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the changes of open probability (Po) of large conductance Ca(2+)-activated K(+) channel (BK channel) in diabetic coronary smooth muscle cells and elucidate the underlying cellular electrophysiology mechanisms of coronary dysfunction.</p><p><b>METHODS</b>Rat coronary smooth muscle cells were isolated from control group and diabetic group. BK single channel currents were recorded by patch clamp technique in inside-out configuration. Open probabilities were calculated and compared between two groups. After exposure to DHS-1, a specific BK channel activator, Po at 0.2 and 1 µmol/L free Ca(2+) were compared between control and diabetic groups.</p><p><b>RESULTS</b>In the presence of 0.2 µmol/L free Ca(2+), the Po at baseline was significantly lower in diabetic rats than in control rats (0.0032 ± 0.0012 vs. 0.095 ± 0.036, P < 0.05). Cytoplasmic application of DSH-1 significantly increased the Po to 0.335 ± 0.096 (P < 0.05 vs. baseline) in control rats, whereas DSH-1 had no effect in diabetic rats (Po = 0.022 ± 0.018, P > 0.05 vs. baseline). In the presence of 1 µmol/L free Ca(2+), the Po at baseline was also significantly lower in diabetic rats than in control rats (0.210 ± 0.055 vs. 0.458 ± 0.077, P < 0.05). Cytoplasmic application of DHS-1 further robustly enhanced Po to 0.823 ± 0.019 (P < 0.05 vs. baseline) in control rats and to 0.446 ± 0.098 in diabetic rats (P < 0.05 vs. baseline of diabetic rats; P < 0.05 vs. control rats with DHS-1).</p><p><b>CONCLUSION</b>The decrease of Po of BK single channel in coronary smooth muscle cells may be a potential cause for coronary dysfunction in diabetic rats.</p>
Texto completo:
1
Índice:
WPRIM
Assunto principal:
Ratos Sprague-Dawley
/
Técnicas de Patch-Clamp
/
Vasos Coronários
/
Biologia Celular
/
Miócitos de Músculo Liso
/
Diabetes Mellitus Experimental
/
Canais de Potássio Ativados por Cálcio de Condutância Alta
/
Metabolismo
/
Músculo Liso Vascular
Limite:
Animals
Idioma:
Zh
Revista:
Chinese Journal of Cardiology
Ano de publicação:
2012
Tipo de documento:
Article