[Effects of intraperitoneal injection of marrow mesenchymal stem cells on intestinal barrier in acute pancreatitis]

To explore the effects of intraperitoneal injection of mesenchymal stem cells (MSC) on intestinal barrier in serve acute pancreatitis (SAP) rats.MSC were harvested and cultured from femurs of one male SD rat. And 30 female SD rats were divided into 3 groups: control group (n = 6), SAP group (n = 12) and MSC transplantation group (n = 12). SAP was induced by intraperitoneal injection of L-arginine (2 g/kg) twice in SAP and MSC groups. In MSC group, the third-generation MSC (5×10(6)) were injected intraperitoneally once daily for 3 days. All rats were sacrificed after 72 h. The histomorphologic alternations of small intestine were measured to evaluate the therapeutic effect of MSC transplantation. Reverse transcription (RT)-PCR were used to identify the expression of TNF-α mRNA and IL-1β mRNA in small intestine and pancreas. Small intestine and pancreatic samples were examined for the engraftment of donor-derived MSC by Y chromosome in situ hybridization analysis.Compared with SAP group, histomorphologic alternations of small intestine significantly lower in MSC group (4.17 ± 0.28 vs 3.00 ± 0.33, P0.05). The relative expression quantity of TNF-α mRNA and IL-1β mRNA in pancreas were both significant higher in SAP and MSC groups than those in control group (3.10 ± 0.73 and 1.92 ± 0.37 vs 0.51 ± 0.24, 4.60 ± 0.59 and 2.43 ± 0.39 vs 1.15 ± 0.18, all P0.05). Compared with SAP group, the expression quantity of TNF-α mRNA and IL-1β mRNA in pancreas significantly lower in MSC group (both P0.05). The relative expression quantity of TNF-α mRNA and IL-1β mRNA in small intestine were both significant higher in SAP and MSC groups than those in control group (2.73 ± 0.91 and 1.55 ± 0.48 vs 0.62 ± 0.20, 5.20 ± 0.94 and 2.10 ± 0.34 vs 0.99 ± 0.10, all P0.05). The expressions of TNF-α mRNA and IL-1β mRNA in MSC group were lower than those in SAP group (both P0.05). Sry gene was not detected in pancreatic and intestinal tissue of MSC-treated rats.Syngraft MSC exert protective effects on pancreas and small intestine injury. And their beneficial effects are primarily mediated via indirect actions but not by their differentiation into target cells.