OBJECTIVETo study the bone marrow mesenchymal stem cells (MSC) settled in rats after small intestinal transplantation.

METHODSBone marrow MSCs were taken from 1-month male Lewis rats, isolated and cultured by density gradient centrifugation and differential adherent culture. The surface antigens (CD29, CD90, CD34 and CD45) of MSC were identified by flow cytometry. Final concentration of 5 μg/L CFSE was used to mark the third generation of MSCs. Adult male inbred line F344 rats were used as donor and adult male Lewis rats as acceptor. A heterotopic intestinal transplant rat model was established by F344 to Lewis. Labeled MSCs were injected into model rats through vena dorsalis penis after operation. Tissues at postoperative 7-day were collected for frozen pathology to reveal the location of transplanted MSCs under fluorescence microscope.

RESULTSMSCs were successfully isolated from rat bone marrow. The average positive expression rates of surface antigens CD29, CD90, CD34 and CD45 were 96.48%, 99.77%, 2.41% and 1.39% respectively. MSCs were successfully and effectively marked with CFSE. Seven days after operation, a large number of green fluorescence could be observed in transplanted intestine, spleen and thymus. Autograft intestinal tissues only showed trace fluorescence, and the heart, liver and lung tissue basically did not present the green fluorescence.

CONCLUSIONBone marrow MSCs can settle in transplanted small intestine of rat.