Objective: To observe the effect of hyperlipidemia and atherosclerosis on rat myocardial expression of calcium-sensing receptor and apoptosis.
Methods: The rat atherosclerosis model was induced by intraperitoneal injection of VD(3) (6 x 10(5) U/kg) and high cholesterol diet. Wistar rats were divided into two groups: (1) Control group; (2) AS group (n = 12 each). The expressions of CaSR, Bcl-2, Bax and caspase-3 were analyzed by Western blot and RT-PCR. Apoptotic cells were observed by TUNEL assay. The morphological changes of abdominal aorta and cardiac tissues were observed under optical and electro microscopes. The activity of LDH, CK, SOD and the content of MDA were assayed with ultraviolet spectrophotometer. The level of cTnT was detected by electrochemical immunofluorescence.
Results: Compared with control group, the activity of LDH and CK, the content of MDA and cTnT, the apoptosis index, the expression of CaSR, Bax and caspase-3 were significantly increased, but the SOD activity and Bcl-2 expression were significantly decreased, the myocardial ultrastructure injury was significantly aggravated in the AS group (all P < 0.05).
Conclusion: Hyperlipidemia and atherosclerosis can up-regulate myocardial calcium-sensing receptor expression, promote myocardial apoptosis, aggravate oxidative stress and myocardial ischemia.