Protective Effects Of α-lipoic On High Glucose Induced Cardiac Myocytes Hypertrophy In Neonatal Rats

ObjectiveStudy the action mechanism of Alpha Lipoic Acid on the neonatal ratcardiac myocyte hypertrophy induced by high glucose from the perspective ofsignal transduction pathway of PKC/NF-κB/c-fos.MethodPrimarily culture the cardiac myocyte of1~3dSD neonatal rat’s heart tip andinduce the cardiac myocyte hypertrophy by high glucose. The experiment isdivided into8groups:1) control group.2) HG (25.5mmol L-1) group.3)HG+α-LA (50μmol L-1) group.4) HG+α-LA (100μmol L-1) group.5) HG+α-LA(200μmol L-1) group.6) HG+α-LA (300μmol L-1) group.7) HG+Ro-31-822050(nmol L-1) group.8) HG+BAY11-70825(μmol L-1) group. After48hours ofculturing the myocyte with medicine, test the surface area of the myocyte andtest the protein content of the cardiac myocyte by the method of coomassieblue staining and test the cardiac myocyte PKC-α（Protein kinase C,PKC-α）,NF-κB（Nuclear transcription factor-kappaB） and the protein expression ofc-fos (FBJ osteosarcoma oncogene)by the method of Wesrtern blot. Test themRNA expression of cardiac myocyte TNF–α by the method of RT-PCR. ResultsContrasted to the control group, in the HG group, the neonatal rat cardiacmyocyte hypertrophy, the surface area of the cardiac myocyte increases (P﹤0.01), protein content increases (P﹤0.01), the expression of PKC-α, NF-κB,c-fos and TNF-αrises (P﹤0.01) and meanwhile the mRNA expression of TNF-αincreases significantly (P﹤0.01). α-LA can reduce the neonatal rat cardiacmyocyte hypertrophy, reducing the surface area and protein content (P﹤0.05or P﹤0.01) of cardiac myocyte. Contrasted to the HG group, the proteinexpression of PKC-α、NF-κB、 TNF-αand c-fos in the cardiac myocyte inHG+α-LA (300μmol L-1) group decreases significantly (P﹤0.01). Contrastedto the HG+model group, the condition of cardiac myocyte hypertrophy in α-LAgroup has been improved greatly: The protein content of cardiac myocytereduces significantly (P﹤0.05orP﹤0.01), the surface area of cardiac myocytereduces greatly P﹤0.05or P﹤0.01) and the expression of PKC-α, NF-κB,TNF-α and c-fos as well as the mRNA expression of TNF-α reducessignificantly (P﹤0.05or P﹤0.01) and (P﹤0.05) respectively.Conclusionα-LA has a protective impact on the neonatal rat cardiac myocytehypertrophy induced by high glucose whose mechanism may be connected tothe signal transduction pathway that inhibits PKC/NF-κB/c-fos.