Effects Of Growth Hormone On Intestinal Bacteria Translocation And Intestinal Permeability In Rats With Sepsis

The human gastrointestinal tract is colonized by a dense population of microorganisms, referred to as the bacterial flora. The gut is a complex organ, in addition to nutrient absorption, the gut must function as a barrier to prevent the spread of intraluminal bacteria and endotoxin to systemic organs and tissues. However, under certain experimental and clinical circumstances, this intestinal barrier function becomes overwhelmed or impaired, resulting in the movement of bacteria and/or endotoxin to the mesenteric lymph nodes (MLN) and systemic tissues. This process of bacteria and their products crossing the intestinal mucosal barrier and spreading systemically has been termed bacterial translocation (BT). It is reported that BT can lead to SIRS, Sepsis and MODS, even can made patients to die.Growth hormone (GH), a strong anabolic hormone, has been reported to show the prevention of nitrogen loss and the protein sparing effect when it was administered to the patients with trauma, injury, burn or the patients after operation. There are also controversies concerning the effect of GH on gut barrier. In this study, we investigated the effects of growth hormone on intestinal bacteria translocation and intestinal permeability in rats with sepsis. PART 1 Effects of growth hormone on intestinal bacteria translocation in rats with sepsisObjective:To confirm the influence of growth hormone on intestinal bacteria translocation in rats with sepsisMethods:Seventy-two male Sprague-Dawley (SD) rats, weighing 200-250g, were randomly divided into four groups:control group (n=18), growth hormone group(n =18),LPS group (n=18)and LPS plus growth hormone group(n=18).Each group were further randomly divided into jejunum, ileum and colon groups. Murine septic model was established through intraperitoneal injection of LPS, sepsis plus gowth hormone group was followed by growth hormone, growth hormone group was injected growth hormone subcutaneously. Escherichia Coli(E.coli) labeled with green fluorescent protein (GFP) were injected into each intestinal segment through the tubes. The mesenteric lymph nodes (MLNs) were taken for frozen section and examined for translocation of GFP labeled E. coli using fluorescence microscopy and specimens of the intestinal wall of jejunum, ileum and colon used for histological examination on the time of 24 hours.Results:The number of E.coli labeled with GFP in LPS groups was higher than that in control group (P<0.01), and the ileum group was the highest one (P<0.01). While in LPS plus GH group, the number of GFP-labeled E.coli was lower compared with LPS group (P<0.05). After injection of LPS in jejunum and ileum group, mucosal atrophy, denudation and collapse of the villus were observed. But the destruction of colon was the slightest. While in LPS plus GH group, the destruction of every segment of intestinal mucosa was reduced.Conclusion:Sepsis could induce intestinal bacterial translocation in rats, while the ileum is the serious places in intestines and GH can reduce the incidence of intestinal bacteria translocation in sepsis PART 2 Effects of growth hormone on intestinal permeability in rats with sepsisObjective:To confirm the influence of growth hormone on intestinal permeability in Rats with SepsisMethods:The groups and models are the same with the part 1. Lactulose and Mannitol were injected into the bowel lumen, urine was collected for a total of 8 h and intestinal permeability was assessed by HPLC. At the time of 24 hours all animals were killed and the apoptosis of intestinal epithelium cells were tested by flow cytometer (FCM) using Annexin-V/PI.Results:The intestinal permeability and the apoptosis index in intestinal epithelium cells in LPS groups were higher than control groups (P<0.01).In LPS plus GH group a significant decrease (P<0.05) was noted. The ileum group was higher compared with the jejunum group and colon groups in LPS groups (P<0.01).Conclusion:Sepsis can induce damage of the gut, the intestinal permeability and apoptosis are higher than usual while the ileum is the serious places and GH can reduce the increased intestinal permeability and the apoptosis index in intestinal epithelium cells in sepsis.