T-type calcium channel effects on RyR and IP_3R of sarcoplasmic reticulum in atrial myocytes during atrial fibrillation.
- VernacularTitle:心房颤动时心房肌细胞T型钙通道对肌浆网RyR、IP_3R表达及功能的影响
- Author:
Yuansheng LIU
;
Jihong GUO
;
Xuebin LI
- Publication Type:Journal Article
- Keywords:
Atrial fibrillation Calcium channel Signal transmission Ryanodine receptors Inositol 1,4,5-triphosphate receptors
- From:
Chinese Journal of Practical Internal Medicine
2003;0(01):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To inquire into T-type calcium channel effects on RyR and IP 3R of sarcoplasmic reticulum in atrial myocytes during atrial fibrillation.Methods Ten dogs underwent continuous rapid atrial pacing (500 beats/min) to create persistent atrial fibrillation.In five rapidly-paced dogs,mibefradil dihydrochloride was given beginning 2 days after pacemaker implantation,continuing until the twenty-fourth week.A group of size-matched dogs (n=5) without given mibefradil was used as a pure atrial fibrillation group.Another group of size-matched dogs (n=5) without pacemaker implantation was used as a control group.Canine atrial myocytes isolated by enzymatic dissociation were used to study T-type Ca 2+ channel blocker effects on expression and function changes of RyR and IP 3R in atrial myocytes by confocal microscopy.Results RyR/IP 3R ratio (0.2965?0.01812) was markedly lower than that of control group (2.7043?0.2293),but there was no difference compared with that of atrial fibrillation group (0.2472?0.1355).Ca 2+transient of atrial myocytes was nremarkably changed (1.3031?0.1056)(P
