To investigate the influence of breviscapine on the cardiac structure and 
function in diabetic cardiomyopathy rats as well as the expression of protein 
kinase C (PKC) and Ca(2+)-cycling proteins expression. Diabetes was induced in 
male Sprague-Dawley rats by a single intraperitoneal injection of streptozotocin 
and the control rats were injected with saline. After the induction of diabetes 
for 4 weeks, the animals were divided into different groups: (1) normal rats as 
control; (2) diabetic rats; (3) diabetic rats with administration of 
breviscapine (10 or 25 mg kg(-1) day(-2)). After treatment with breviscapine for 
6 weeks, the invasive cardiac function and echocardiographic parameters were 
measured, and heart tissue was obtained for electron microscope study. The 
expression of protein kinase C (PKC) and calcium handling regulators, such as 
protein phosphatase inhibitor-1 (PPI-1), phospholamban (PLB) and Ca(2+)-ATPase 
(SERCA-2), ryanodine receptor (RyR) were detected by western blot or RT-PCR. The 
activity of SERCA-2 was measured using Ca(2+)-ATPase kit. Diabetic rats showed 
impaired cardiac structure and function compared with control rats. The 
expression of PKC, PLB increased significantly, while the PPI-1, SERCA-2 and RyR 
expression decreased. Treatment with breviscapine could reverse the cardiac 
dysfunction and structure changes in diabetic cardiomyopathy rats, and decrease 
the expression of PKC and PLB, as well as increase the expression of PPI-1, 
SERCA-2 and RyR. The protective effect of breviscapine was dose related. This 
study showed that breviscapine could regulate the expression of PKC, PPI-1, PLB 
and SERCA-2 and have protective effect on diabetic cardiomyopathy.