ing the left ventricle, up-regulating the number and function of EPCs and increasing therapeutic angiogenesis. Thus, we could examine whether the RGE is a EPCs activator or not. We 14937-32-7 further analyzed the alteration of the SDF-1a/CXCR4 cascade with RGE in vivo and in vitro, to investigate the possible mechanism of RGE on EPCs after MI. high-dose RGE, 1.5 gkg21day21 as compared with 0.38 and 0.75 gkg21day21, which was converted from human oral administration doses, effectively increased bone marrow mobilization of EPCs and migration to peripheral blood; Electrocardiography and Ultrasonic Cardiography Before and after surgery, rats underwent electrocardiography by use of a Micromaxx P04224 system and ultrasonic cardiography by a high-frequency duplex ultrasonic cardiogram system and a transducer. Rats underwent ultrasonic cardiography at day 3, weeks 1, 2 and 4 before sacrificed. The transducer for ultrasonic cardiography was placed at the left thoraces between the 3rd and 4th ribs to obtain B-mode tracings of the heart from just below the level of the papillary muscles of the mitral valve. We obtained left-ventricular enddiastolic diameters and end-systolic diameters with M-mode tracings between the anterior and posterior walls. The time of end-diastole and end-systole was defined as time of maximum and minimum diameter of the left ventricle, respectively, in one heart cycle. Following the American Society of Echocardiology leading-edge method, we obtained 3 images, on average, in each view, which were averaged over three consecutive cycles.The system calculated the left-ventricular end-diastolic volume, left-ventricular end-systolic volume, mass of the left ventricle, left-ventricular fractional shortening and left-ventricular ejection fraction. Materials and Methods Preparations of Rehmannia Glutinosa Extract Rehmannia glutinosa was from the National Institutes for Food and Drug Control. RGE was prepared by alcohol extraction. Briefly, dried Rehmannia glutinosa was soaked with distilled water in a 1:10 volume ratio for 24 h, then heated to 80uC for 12 h. The supernatant was collected and ethanol was added to a 3:4 volume ratio. The extracts were stored at room temperature for 24 h and centrifuged at 3000 rpm for 10 min, and the supernatant was mixed with ethanol in a 1:4 volume ratio. Then extracts were incubated at room temperature for an additional 24 h and centrifuged at 3000 rpm for 10 min. Ethanol was evaporated from the supernatant. The extract was diluted in H2O and stored at 20uC overnight. This process was repeated 3 times. The final extracts were concentrated under reduced pressure and filtered, lyophilized, and serially stored at 4uC. The yield of dried extract from starting crude materials was 22.5% . The RGE was dissolved in 14530216 saline or phosphate-buffered saline for experiments. EPC Identification and Assessment of Function Isolation and cultivation of EPCs. 10 ml peripheral blood was obtained from rats by aspiration of the heart. Bone-marrow cells were obtained by flushing the cavity of femurs, tibias, and humerus with growth medium EBM-2. Peripheral blood and bone marrow mononuclear cells 
were isolated by Ficoll density-gradient centrifugation. 10 million 15771452 isolated cells were resuspended in growth medium EBM-2 and plated in 25-cm2 culture flasks. After 48 h, non-adherent cells were discarded and growth medium was changed every 2 days. Identification of EPCs. Direct fluorescent staining was used to detect dual binding of fluore
