[Changes of myocardial function in diabetic rats and its mechanism]

To investigate the role of calcium-sensing receptor (CaSR) in the decrease of cardiac function in type 2 diabetic rats.

Wistar rats were randomly divided into 3 groups including control, diabetic-4 week and diabetic-8 week groups. Rats in the diabetes group were fed with high-glucose and high-fat diet, and intraperitoneal injection of streptozocin (STZ,30 mg/kg) was conducted 4 weeks later to establish a type 2 diabetes model. Cardiac morphological changes were observed by HE staining, cardiac function was detected by echocardiography, and CaSR and PKC-αprotein expressions in cardiac tissue were detected by Western blot.

Compared with the control group, the myocardium of diabetic rats showed irregular contraction zone, decreased expression of CaSR protein, increased expression of PKC-α protein, decreased systolic and diastolic functions, and gradually worsened with the prolongation of the course of the disease.

Hyperglycemia inhibits the expression of CaSR protein in myocardium of diabetic rats by activating PKC-α, which can cause intracellular calcium disorder and lead to decreased cardiac function.