ObjectiveTo evaluate the dynamic changes of blood flow and blood pressure of acute hindlimb ischemia of rats by laser Doppler flowmetry (LDF) and laser Doppler perfusion imaging (LDPI). MethodsThe acute hindlimb ischemia model of rats was established by resection of rats femoral arteries of left hindlimb. The blood flow and blood pressure between operated and nonoperated hindlimbs were examined by LDF on 2, 7, 14, 28, and 49 d after operation. And the blood flow was evaluated by LDPI on 7 d after operation. ResultsAll rats survived after operation and no hindlimb necrosis occurred. The mean score was 2 on 14 d after operation and 1 on 49 d after operation. The ratio of blood flow between operated and nonoperated hindlimbs on 2 d after operation significantly increased from 1 to 1.31±0.439 (P=0.021). The ratio of blood flow on 7 d (0.82±0.538) and 14 d (0.93±0.294) after operation was significantly lower than that on 2 d after operation (P=0.032 and P=0.019), although the difference between the two former was not significant (P=0.502). Furthermore, the ratio of blood flow on 28 d after operation reached the bottom (0.41±1.970), which was obviously lower than that on 2, 7, and 14 d after operation (P=0.004, P=0.007, and P=0.006). The blood flow of operated hindlimbs recovered approximately the value before operation (0.98±0.093), which was significantly lower than that on 2 d (P=0.010), higher than that on 28 d (P=0.005), but not different from that on 7 d and 14 d after operation (P=0.126 and P=0.382). The ratio of blood pressure between operated and nonoperated hindlimbs on 2 d after operation significantly increased from 1 to 0.47±0.375 (P=0.031). The ratio of blood pressure decreased on 7 d after operation (0.44±0.118), which was not different from that on 2 d after operation (P=0.203). Furthermore, the ratio of blood pressure on 14 d after operation reached the bottom (0.35±0.115), which was obviously lower than that on 2 d and 7 d after operation (P=0.001 and P=0.036). On 28 d after operation, the ratio of blood pressure increased (0.54±0.146), which was significantly higher than that on 14 d after operation (P=0.008), while not different from that on 2 d (P=0.493) and 7 d after operation (P=0.551). The ratio of blood pressure recovered approximately the value before operation (0.97±0.094), which was significantly higher than that on 2, 7, 14, and 28 d (P=0.013, P=0.021, P=0.002, and P=0.031). ConclusionAcute hindlimb ischemia model of rats can be established by resection of rats femoral arteries of left hindlimb and the most serious stage of hindlimb ischemia is on 14-28 d after operation. LDF and LDPI are of importance for monitoring the dynamic changes of rats hindlimb ischemia after operation.
ObjectiveTo study the effect of exogenous insulin on inducing angiogenesis and the expression of vascular endothelial growth factor (VEGF) of hindlimb ischemia of rats with diabetic. MethodsThe hindlimb ischemic model of diabetic rat was established by the ligation of femoral blood vessels of hindlimb in twenty healthy male SD rats and which were divided into model group (n=10) and treatment group (n=10). Another 10 normal rats were selected as control group. Then the expression of VEGF protein and capillary density of muscle tissues of rat hindlimb were detected by Western blot analysis and alkaline phosphatase (APK) stain method, respectively. ResultsThe differences of body weight and blood glucose level of rats before operation and on day 7 after operation were not significant in the control group (Pgt;0.05). The body weight of rat was significantly lower on day 7 after operation than that before operation in the model group (Plt;0.05), while the difference of blood glucose level of rats was not significant in the model group (Pgt;0.05). The body weight and blood glucose level of rat significantly decreased in the treatment group on day 7 after subcutaneous injection of insulin as compared with the level before operation (Plt;0.05). Compared with the control group, the body weight decreased and blood glucose level increased in the model group and treatment group, and the difference was significant (Plt;0.05, Plt;0.01). The body weight of rat in the treatment group was not different from that in the model group (Pgt;0.05), but the blood glucose level of rat on day 7 after operation in the treatment group was significantly lower than that in the model group (Plt;0.05). The relative expression of VEGF protein of muscle tissues of ischemic hindlimbs in the treatment group (155.06±10.26) was significantly higher than that in the model group (94.30±11.23), Plt;0.05, while no expression was found in the control group. The capillary density of muscle tissues of right hindlimb in the control group was significantly higher than that in the model group or treatment group (Plt;0.05), and furthermore, which was higher in the treatment group than that in the model group (Plt;0.05). The difference of capillary density of muscle tissues of left hindlimb was not different among three groups (Pgt;0.05). The capillary density of muscle tissues of right hindlimb was not different from that of left hindlimb in the control group (Pgt;0.05) and which was significantly lower than that of left hindlimb in the model group or treatment group (Plt;0.05). ConclusionInsulin may increase the expression of VEGF protein in ischemic muscle tissue of diabetic rats and protect the ischemic muscle.