RESUMEN
Objective To establish a rat model of cardiac hypertrophy induced by isoproterenol(ISO),and to study its basic characteristics . Methods Cardiac hypertrophy was induced in rats with ISO. The model rats received subcutaneous injections of 5 mg/kg ISO every day for 14 days. Results The heart weight/body weight and left ventricular weight/body weight ratios in model rats were significantly increased. The serum hydroxyproline level was significantly increased ,the superoxide dismutase level was significantly decreased ,and the malondialdehyde level was sig?nificantly increased in model rats. Conclusion The rat model of cardiac hypertrophy is successfully created by subcutaneous injection of ISO for 14 days. This model can be used in study of the mechanism of cardiac hypertrophy.
RESUMEN
Objective To construct expression vectors of calmodulin(CaM)mutants N2 and C2,and to express,purify,and identify the mutant proteins,in order to study the interactions between CaM and calcium channels. Methods The cDNA of N?lobe and C?lobe of CaM were used to prepare the cDNA of N2 and C2. Next,the recombinant cDNAs were cloned into a pGEX?6p?3 plasmid,and the recombinant plasmids were trans?ferred into E.coli BL21 cells. The transfected BL21 cells were stimulated with IPTG. The fusion proteins were extracted by ultrasonication and puri?fied by using GS?4B beads. Finally,protein activity was identified by the pull?down assay. Results Both the restriction digestion map and the DNA sequence identification results confirmed that the recombinant plasmids were successfully constructed. SDS?PAGE results showed high purity and concentration of N2 and C2 proteins. Their activities and binding abilities with the calcium channel fragment were confirmed by the pull?down assay.Conclusion In this study,expression vectors of N2 and C2 are successfully constructed,and physiologically active N2 and C2 CaM mutant proteins are obtained.