Résumé
Objective To observe the expressions of voltage-gated sodium channel (NaCh)αsubunits in adult rat ventricular myocytes.Methods Single ventricular myocytes were isolated from adult rat heart.Expressions of various αsubunits (Nav1.1,Nav1.2,Nav1.3,Nav1.5,Nav1.6 and Nav1.7)of NaCh in the ventricular myocytes were detected by immunocytochemistry staining.Sodium current was recorded by whole-cell patch clamp method. Results The neuronal subunits Nav1.1,Nav1.6 and Nav1.7 as well as the cardiac subunit Nav1.5 of NaCh were expressed in adult rat ventricular myocytes.Nav1.1,Nav1.5 and Nav1.7 were distributed along the cell membrane of the ventricular myocytes and around the transverse tubule;Nav1.6 was labeled along the cell membrane by lengthways.All these subunits were not colocalized with Cx43 at the intercalated disc.Both transient sodium current (I Na,T )and late sodium current (I Na,L )were recorded from adult rat ventricular myocytes.Conclusion Various neuronal subunits (Nav1.1,Nav1.6 and Nav1.7)as well as cardiac subunit (Nav1.5 )of NaCh were expressed in adult rat ventricular myocytes,which is important for normal function of I Na,T and I Na,L .
Résumé
Objective To establish a method to isolate single sinoatrial node cells of adult rats and observe the cells'morphological structure and the expression of sodium channel subtype so as to provide experimental basis for further research on the role of sodium channel in sinoatrial node function.Methods We isolated adult rat sinoatrial node tissue and cut it into slices about 2 mm in width,digested the slices with type Ⅱ collagenase combinate protease, and observed the cells' morphological structure. We then performed immunofluorescence staining with HCN4 and laser confocal imaging to identify cells and observe the expressions of Nav1 .1 ,Nav1 .2 , Nav1.3,Nav1.5,Nav1.6,Nav1.7,Nav1.8 and Nav1.9.Results The isolated cells had spindle-like,arc-like, and slender and curved shapes,but were mainly spindle-shaped.The stripes of the cells were clear,had good bioactivity and could survive 6-8 hours.Sodium channels Nav1.1,Nav1.5,Nav1.6,Nav1.7,Nav1.8,and Nav1.9 were positively expressed in adult rat sinoatrial node cells,while Nav1 .2 and Nav1 .3 were negatively expressed. Conclusion The method of digesting and isolating adult rat sinoatrial node cells with type Ⅱ collagenase combinate protease is reliable,and sodium channel subtypes are differently expressed in sinoatrial node cells.
Résumé
Objective To observe the expressions of voltage-gated sodium channel (NaCh)αsubunits in adult rat ventricular myocytes.Methods Single ventricular myocytes were isolated from adult rat heart.Expressions of various αsubunits (Nav1.1,Nav1.2,Nav1.3,Nav1.5,Nav1.6 and Nav1.7)of NaCh in the ventricular myocytes were detected by immunocytochemistry staining.Sodium current was recorded by whole-cell patch clamp method. Results The neuronal subunits Nav1.1,Nav1.6 and Nav1.7 as well as the cardiac subunit Nav1.5 of NaCh were expressed in adult rat ventricular myocytes.Nav1.1,Nav1.5 and Nav1.7 were distributed along the cell membrane of the ventricular myocytes and around the transverse tubule;Nav1.6 was labeled along the cell membrane by lengthways.All these subunits were not colocalized with Cx43 at the intercalated disc.Both transient sodium current (I Na,T )and late sodium current (I Na,L )were recorded from adult rat ventricular myocytes.Conclusion Various neuronal subunits (Nav1.1,Nav1.6 and Nav1.7)as well as cardiac subunit (Nav1.5 )of NaCh were expressed in adult rat ventricular myocytes,which is important for normal function of I Na,T and I Na,L .
Résumé
Objective To establish a method to isolate single sinoatrial node cells of adult rats and observe the cells'morphological structure and the expression of sodium channel subtype so as to provide experimental basis for further research on the role of sodium channel in sinoatrial node function.Methods We isolated adult rat sinoatrial node tissue and cut it into slices about 2 mm in width,digested the slices with type Ⅱ collagenase combinate protease, and observed the cells' morphological structure. We then performed immunofluorescence staining with HCN4 and laser confocal imaging to identify cells and observe the expressions of Nav1 .1 ,Nav1 .2 , Nav1.3,Nav1.5,Nav1.6,Nav1.7,Nav1.8 and Nav1.9.Results The isolated cells had spindle-like,arc-like, and slender and curved shapes,but were mainly spindle-shaped.The stripes of the cells were clear,had good bioactivity and could survive 6-8 hours.Sodium channels Nav1.1,Nav1.5,Nav1.6,Nav1.7,Nav1.8,and Nav1.9 were positively expressed in adult rat sinoatrial node cells,while Nav1 .2 and Nav1 .3 were negatively expressed. Conclusion The method of digesting and isolating adult rat sinoatrial node cells with type Ⅱ collagenase combinate protease is reliable,and sodium channel subtypes are differently expressed in sinoatrial node cells.