OBJECTIVE

To investigate the changes of the myocardial cells in chronic epileptic rat model and to observe the expression of calcium sensing receptor(CaSR) and mitogen-activated proteinkinase(MAPK)pathway changes in epilepsy rats.

METHODS

The chronic epileptic rat model was induced bypentetrazole (PTZ). Adult male Wistar rats were divided into 5 groups randomly, and there were 12 rats in each group. The rats in model group were treated with a sub-convulsivedose of PTZ (35 mg/kg) by intraperitoneal injection for 28 d. After stopping a week, the same dose of PTZ test was conducted. The control group was treated with isovolumetric saline instead of PTZ by intraperitoneal injection. According to Racine behavior grading standards the rat emerged two levels above epileptic seizure 5 consecutive times, which was considered the chronic epilepsy model successful ignition. The intervention factors included spermine(calcium-sensing receptor agonist, 3 mol/L) and Chalhex231(calcium-sensing receptor inhibitor, 2 mol/L). The serum creatine kinase (CK) and creatine kinase isoenzyme(CK-MB)were detected. The cardiac functions, morphological changes of rat myocardial tissue, myocardial cell ultrastructure, myocardial cell calcium sensing receptor and extracellular regulated protein kinase (ERK), p-ERK, p-JNK expression were carried out.

RESULTS

Compared with normal control group, CK, CK-MB inPTZ group were increased obviously. The cardiac compliance and left ventricular function were decreased, E/A<1 by echocardiography. The myocardial ultrastructure showed serious injury. The expressions of CaSR and p-JNK were increased, but the expression of p-ERKwas decreased. Spermine could promote the expressions of CaSR and p-JNK, and decrease the expression of p-ERK in epilepsy; however, the role of Chalhex231 wasopposite.

CONCLUSIONS

The level of CaSR expression increased in chronic epileptic rat model. CaSR activated the expressions of MAPK of the myocardial cells,andthen influenced the cardiac myocyte apoptosis.