BACKGROUND; Studying the pathogenesis and rule of intestinal barrier damage under exercise stress will provide theoretical evidence for preparing intestinal barrier protectant under this state.OBJECTIVE : To observe the changes in intestinal barrier of rats following different intensities of swimming exercise. DESIGN: Randomized controlled animal experiment.SETTING: Laboratory of Exercise Sciences & Sports Medicine, Huibei University; Basic Laboratory, Medical College, Wuhan University.MATERIALS: Thirty-six healthy male SD rats, aged 3 weeks, were involved and randomized into 3 groups: control group (n =10), proper exercise group (n =12) and excessive exercise group (n =14). The rats of three groups were raised in the same condition.METHODS:①Control group: Rats did not exercise normally. ②Proper exercise group: Rats swam without loading. In the first 3 days, they adaptatively swam for 30 minutes and gradually for 60 minutes within 1 week, then they swam once a day, 6 times a week, 6 weeks in total. ③Excessive exercise group: In the first 3 days, they adaptatively swam for 30 minutes and gradually for 120 minutes within 1 week. After trained for 1 week, they were given excessive swimming training. Then, they were forced to swan once a day, 6 times a week, within 4 weeks successively. Within later 2 weeks, the rats were forced to swan once in the morning and evening separately, 6 times a week.MAIN OUTCOME MEASURES:①Intestinal barrier parameter: intestinal mucosal permeability, plasma endotoxin, becterium shift rate.②Intestinal mucosal membrane structure.RESULTS: Thirty-six rats were involved in final analysis.①After excessive exercise, plasma endotoxin of rats was doubly increased, intestinal mucosal permeability was enhanced by 2.5 times, and bacterium shift rate was increased by 230%.②Proper exercise had no obvious influences on the structure of intestinal mucosal membrane tissue of rats, and excessive exercise expanded Golgi complex in the intestinal epithelial cells and rough endoplasmic reticulum of rats, caused severe edema of epithelial cells and infiltration of inflammatory cells.CONCLUSION: Proper exercise improves intestinal function of body; excessive exercise causes intestinal barrier injury of body and pathological syndrome of digestive system.

Objective To prepare targeted microbubbles which load anti-VEGFR-3 and observe the targeting effect in vitro.Methods Targeted microbubbles loaded VEGFR-3 antibody were prepared and the targeting effect in vitro were tested by direct and indirect methods.Direct method took off-line analysis by image analysis software IPP and statistical analysed with SPSS software package.Indirect method took direct observation the target binding effect after incubation and centrifugal sedimentation.Results Image software IPP results showed that the quantity of microbubbles in targeted-group was obviously more than ordinary group.The average microbubbles per field in targeted-group was (151 ±20).The average microbubbles per field in ordinary group was ( 12 ±4 ) microbubbles, the numbers of combined microbubbles between targeted-group and ordinary-group had significant differences ( t=19.19,P<0.01).The indirect method results showed that, compared with ordinary group, the microbubbles in targeted-group could combined with cell gradually.Conclusion Targeted microbubbles load anti-VEGFR-3 have a better contrast effect than common microbubbles.