Effects Of Atherosclerosis On The Plasma Levels Of ANP And Its Receptor NPR-A

Objective:Establishing atherosclerotic rat model by the high fat diet, to observe the change of concentration of atrial natriuretic peptide(ANP) in plasma, the expression of natriuretic peptide receptor A (NPR-A) in aortic tissue, and the change of concentration of cyclic guanosine monophosphate (cGMP). Investigating the influence of atherosclerosis to concentration of ANP and expression of NPR-A and cGMP.Methods:the 16 healthy male Wistar rats, 8 weeks old, weighing 190g-220g, were randomly divided into AS group and control group, with 8 rats in each group. AS group were fed with high fat diet, the control group with basic diet for 16 weeks. Commonlyused method was used to detected total cholesterol, triglyceride, low density lipoprotein cholesterol, high density lipoprotein cholesterolin two groups of ratsplasma; The content of ANP was determined by iodine [125I] kit cardionatrin radioimmunoassay; HE staining and immunohistochemical staining were used to observe the distribution of receptors of NPR-A in vascular tissue; Determination of expression of NPR-A receptor in vascular tissue by Western blot method. Determination of cGMP concentration in aortic tissue by ELISA cGMP detection kit.Results:In AS group, the levels of TC and TG, LDL-C, increased significantly compared with the control group (P<0.01), the level of HDL-C in AS group was significantly lower than that in the control group P<0.05). In AS group, the levels of ANP, increased significantly compared with the,control group (P<0.01). The result of HE staining showed thesmooth lumen of vascular endothelial, the clearboundaries of intima and media and adventitia, and smooth muscle cells arranged in neat rows in control group; Thickening of the intima visible plaque, lipid deposition in AS group. Immunohistoch -emical staining results showed that NPR-A in AS group were less than that in control group (P<0.01). Western blot results showed that the expression of NPR-A in AS group were lower than that in control group(P<0.01). The results of ELISA showed that the concentrations of cGMP in AS group were significantly lower than those in control group (P<0.01)Conclusion:Atherosclerosis lead to increasing of concentration of ANP in plasma, which decreased the expression of NPR-A in aortic tissue, reduced the effective combination of ANP and its receptor, and decreased the concentration of cGMP in aortic tissue.