Effects of MS23 on the vascular myogenic responses and the myocyte voltage-gated K+ channel currents of diabetic rat coronary artery
10.13699/j.cnki.1001-6821.2018.08.010
- VernacularTitle:MS23对糖尿病大鼠冠状动脉肌原性反应和电位依赖性钾通道的影响
- Author:
Yu LIU
1
;
Yan WANG
;
Qi-Ying SONG
;
Peng-Mei GUO
;
Long-Gang NIU
;
Ming-Sheng ZHANG
Author Information
1. 山西医科大学 药理学教研室
- Keywords:
MS23;
coronary artery;
diabetes;
vasorelaxation;
voltage-gated potassium channel
- From:
The Chinese Journal of Clinical Pharmacology
2018;34(8):949-952
- CountryChina
- Language:Chinese
-
Abstract:
Objective To study the effects of a new phosphodiesterase inhibitor MS23 on the myogenic responses of diabetic rat coronary artery (RCA) and the myocyte potassium currents via the voltage-gated potassium channels (Kv).Methods Rats were rendered diabetic with a peritoneal injection of streptozocin at 60 mg · kg-1.At the 4th week after treatment,the diabetic rats were randomly divided into model group,low-dose,and high-dose groups of MS23 (0.3 mg · kg-1 and 1.0 mg · kg-1 orally administrated once a day for 8 weeks),while the normal rats were set as the control group.Model group and control group were fed with 0.9％ NaCl of equal volume once a day from the fourth week to the twelfth week.A wire myograph was used to observe the myogenic effects of isolated RCA.The Kv currents of single rat coronary arterial smooth muscle cell (RCASMC) were studied with patch clamp.Results After administration,the maximum vasorelaxations of RCA to acetylcholine in control group,model group,low-dose,high-dose group were (74.45 ± 6.30) ％,(56.84 ± 5.51) ％,(77.52 ± 5.27) ％,(86.33 ± 8.88) ％,respectively.The maximum vasorelaxations to sodium nitroprusside in the four groups were (88.50 ± 5.81)％,(56.65 ±8.62)％,(80.50 ±7.85)％,(91.60 ±5.97)％,respectively.The maximum RCASMC Kv current density in the four groups were (53.69±4.02) pA · pF-1,(28.25±3.69) pA · pF-1,(38.78±4.55) pA · pF-1,(63.35 ± 4.57) pA · pF-1,respectively.There were significant differences between the model group and the blank group/low-dose group/high-dose group (P ＜ 0.05).The maximum vasorelaxations of diabetic RCA to MS23 (30 μmol · L-1) was (70.69 ± 12.72)％,and preincubation with Kv inhibitor 4-AP (3 mmol · L-1) reduced the MS23-induced maximum relaxation to (34.47 ± 10.08) ％,with significant difference (P ＜ 0.05).Conclusion MS23 relaxes diabetic rat coronary artery and enhances diabetic RCASMC Kv currents.
