Changes of large conductance Ca2+-activated K + channels on coronary smooth muscle cells from diabetic rats
10.3760/cma.j.issn.0253-3758.2010.12.011
- VernacularTitle:糖尿病对冠状动脉平滑肌细胞大电导钙激活钾通道的影响
- Author:
Ru-Xing WANG
1
;
Xiao-Rong LI
;
Zhen-Yu YANG
;
Jie ZHENG
;
Ku-Lin LI
;
Chang-Yin ZHANG
;
Su-Xia GUO
;
Li-Ping SUN
;
Tong LU
Author Information
1. 南京医科大学附属无锡市人民医院
- Keywords:
Diabetes;
Large-conductance calcium-activated potassium channel beta subunits;
Coronary vessels
- From:
Chinese Journal of Cardiology
2010;38(12):1098-1101
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the changes of large conductance Ca2+ - activated K+ channel (BK channel ) on coronary smooth muscle cells from diabetic rats. Methods Streptozotocin-induced rat diabetic animal model was used. Coronary smooth muscle cells were isolated by enzyme digestion. BK currents in control and diabetic groups were recorded by patch clamp technique in whole cell configuration,and BK channel protein expression was detected by Western blot Calcium concentration was measured by fluorescence assay. Results Compared with control group, BK current densities in diabetic group were significantly decreased when test potentials ＞ 100 mV (P ＜ 0.05 ). BK current densities were (275 ± 40)pA/pF in control group (n =8) and (70 ± 10)pA/pF in diabetic group (n =6) at 150 mV test potentials. α-subunit protein expression was similar between the groups ( P ＞ 0. 05 ), however, β1-subunit protein expression was significantly reduced in diabetic group than in control group ( P ＜ 0. 05 ). Calcium concentrations were significantly increased in diabetic group control group (151 ± 18) nmol/L (n =6) than in control group (92 ±7) nmol/L (n =5, P＜0.05). Conclusion Observed β1-subunit downregulation,BK current density decrease and cytosolic calcium concentration increase in smooth muscle cells of diabetic coronary arteries may be associated with coronary dysfunction in diabetic rats.
