Objective: To investigate the contents change after oral Radix Ophiopogon Japonicas polysaccharides MDG-1 in rats by high performance gel permeation chromatograph(HPGPC). Method: Labeling the MDG-1 and detecting replacement of fluoresciniso thiocyate(FITC) then using the HCGPC was in order to detect the contents of MDG-1 in stomach

small intestine

large intestine. To the various parts of the gastrointestinal tract

the stomach were given different doses of F-MDG-1 after pylorus ligation

then suture abdominal while contents were immediately harvested at times 1 h postdose; the stomach were given doses of F-MDG-1 after pylorus ligation

then suture abdominal while contents were immediately harvested at predefined times. The small intestine near the bottom of the cecum were ligated after small intestine were given F-MDG-1 from duodenum near the pylorus then suture abdominal while contents were harvested at predefined times;the large intestine near the anus were ligated after the large intestine were given F-MDG-1 from end of the small intestine near the cecum then suture abdominal while contents were harvested at predefined times

all these contents stored at -20℃ until analysis. Result: The F-MDG-1 in rats stomach following oral administration at different doses of F-MDG-1 after pylorus ligation were described with a degradation model and indicated that F-MDG-1 increases the decomposition along with the dosage to reduce in the stomach

while after oral the same dose indicated that F-MDG-1 increases the decomposition along with the time

but the determination result showed that the content unchanged after pH was adjusted to be neutrality(7.2). The small intestine and the large intestine metabolite process indicated that decomposition of F-MDG-1 increased along with time. Conclusion: The combination of the FITC prelabeling method with the highperformance gel permeation chromatography was confirmed and tested and was feasibile.This methodology should be helpful to other polysaccharides research in gastrointestinal tract. In this study

F-MDG-1 was not decomposition in stomach and mainly metabolism in the intestinal tract as a result of effects of gastrointestinal tract condition and bacterium together.