Alterations of phospholamban expression and cardiac sarcoplasmic reticulum Ca ～(2+)-ATPase activity in diabetic rats / 中国病理生理杂志

ABSTRACT

AIM:To investigate the alterations of phospholamban(PLB)expression and cardiac sarcoplasmic reticulum(SR)Ca 2+-ATPase activity,and the change of cardiac function in rats with diabetes mellitus(DM).METHODS:The diabetes mellitus in male Wistar rats was induced by intraperitoneal injection of streptozotocin.The levels of PLB mRNA and PLB protein,the activity of SR Ca 2+-ATPase and the left ventricular hemodynamics parameters were measured 4 weeks,6 weeks and 8 weeks after DM was induced in rats,while the normal rats served as control group.RESULTS:There was no significant difference in PLB mRNA level and protein level between 4-week-DM rats and normal control rats.6-week-DM rats and 8-week-DM rats had markedly increased PLB mRNA and protein level compared with normal control rats.SR Ca 2+-ATPase activity was not significantly changed in 4-week-DM rats compared with normal control rats,and was markedly depressed in 6-week-DM rats and 8-week-DM rats.LVSP,LVEDP and ?dp/dt max were not significantly changed in 4-week-DM rats compared with normal control rats.In 6-week-DM rats and 8-week-DM rats,LVSP and ?dp/dt max were decreased,LVEDP was increased compared with normal control rats.CONCLUSION:The elevated levels of PLB mRNA and PLB protein contribute to SR Ca 2+-ATPase activity reduction,which leads to cardiac dysfunction in DM rats.