Intestinal microcirculation and gut permeability in acute pancreatitis: early changes and therapeutic implications

Translocation of bacteria from the intestine causes local and systemic infection in severe acute pancreatitis. Increased intestinal permeability is considered a promoter of bacterial translocation. The mechanism leading to increased gut permeability may involve impaired intestinal capillary blood flow. The aim of this study was to evaluate and correlate early changes in capillary blood flow and permeability of the colon in acute rodent pancreatitis of graded severity. Edematous pancreatitis was induced by intravenous cerulein; necrotizing pancreatitis by intravenous cerulein and intraductal glycodeoxycholic acid. Six hours after induction of pancreatitis, the permeability of the ascending colon was assessed by the Ussing chamber technique; capillary perfusion of the pancreas and colon (mucosal and subserosal) was determined by intravital microscopy. In mild pancreatitis, pancreatic capillary perfusion remained unchanged (2.13 c 0.06 vs. 1.98 +/-0.04 nl x min(-1) x cap(-1) [control]; P = NS), whereas mucosal (1.59 +/-0.03 vs. 2.28 +/-0.03 nl x min(-1) x cap((-1))[control]; P <0.01) and subserosal (2.47 +/-0.04 vs. 3.74 +/-0.05 nl x min(-1) x cap((-1))[control]; P <0.01) colonic capillary blood flow was significantly reduced. Severe pancreatitis was associated with a marked reduction in both pancreatic (1.06 +/-0.03 vs. 1.98 +/-0.04 nl x min(-1) x cap(-1) [control]; P <0. 01) and colonic (mucosal: 0.59 +/-0.01 vs. 2.28 +/-0.03 nl x min(-1) x cap((-1))[control], P <0.01; subserosal: 1.96 +/-0.05 vs. 3.74 +/-0.05 nl x min(-1) x cap(-1) [control], P <0.01) capillary perfusion. Colon permeability tended to increase with the severity of the disease (control: 147 +/-19 nmol x thr(-1) x cm(-2); mild pancreatitis: 158 +/-23 nmol x hr(-1) x cm(-2); severe pancreatitis: 181 +/-33 nmol x hr(-1) x cm(-2); P = NS). Impairment of colonic capillary perfusion correlates with the severity of pancreatitis. A decrease in capillary blood flow in the colon, even in mild pancreatitis not associated with significant protease activation and acinar cell necrosis or impairment of pancreatic capillary perfusion, suggests that colonic microcirculation is especially susceptible to inflammatory injury. There was no significant change in intestinal permeability in the early stage of pancreatitis, suggesting a window of opportunity for therapeutic interventions to prevent the later-observed increase in gut permeability, which could result in improved intestinal microcirculation.

[Zinc acts as a protective agent on the mucosal barrier in experimental TNBS colitis]

The aim of this study was to analyze the effect of enterally given zinc on the impaired epithelial barrier function in experimental TNBS colitis in rats. Rats in therapy group were zinc-fed in therapeutic dose. 48 hours after induction of TNBS colitis the rats were killed, the distal colon was resected and mounted into an Ussing chamber. The following electrophysiological measurements were carried out: 1. Flux measurements for Na+ and mannitol as a parameter of paracellular permeability, 2. Resistance measurements of the colon, distinguishing between pure epithelial resistance and resistance of the subepithelial tissue. In TNBS colitis we found a marked increase of both fluxes as a parameter of enhanced paracellular permeability (factor 3). Further there was a drastic reduction of total resistance, and especially of pure epithelial resistance indicating a massive epithelial barrier defect. In rats treated by zinc the increase of paracellular permeability was increased only by a factor of 2, and there was only a moderate decrease of resistance. For the first time we demonstrated zinc to have a protective effect on damaged mucosal barrier function in TNBS colitis. These results confirm the data collected in guinea pigs with malnutrition, whose intestinal integrity could be improved by zinc. Further studies are necessary in order to test whether this protective effect of zinc on mucosa barrier in experimental colitis may be relevant also in human ulcerative colitis.

[Lack of effect of EGF on epithelial barrier function in experimental TNBS colitis]

This study tested the hypothesis that EGF has a protective effect on the intestinal barrier function in experimental TNBS-induced colitis. EGF was given intraperitoneally one hour before and 24 hours after induction of colitis. The rats were killed 48 hours after induction of colitis: The distal colon was resected and mounted into Ussing chambers. Flux measurements were performed for Na+ and mannitol, and epithelial and subepithelial resistances were determined. A semiquantitative histological score was used to grade acute and chronic inflammation. Compared to controls, TNBS caused a 3-fold increase in both fluxy, indicating enhanced paracellular permeability. There rates was a severe reduction of total and epithelial resistances indicating a dramatic defect of epithelial barrier function. EGF failed to improve the electrophysiologic and histologic parameters. Therefore, EFG has no protective effective in experimental TNBS colitis.

[Orthotic treatment and walking ability of patients with myelomeningocele--analysis of influencing factors]

In 106 patients with myelomeningocele, which were fitted with orthotic devices, we analyzed the influence of level of neurologic deficit, scoliosis and contractures of the lower extremities on different walking parameters, e.g. orthotic wearing time, duration of walking and velocity, step length and mobility status. The most important factor is the level of neurologic deficit. From a functional point of view a bilateral hip dislocation can be neglected. Whereas impairment of walking ability is strongly correlated with scoliosis of more than 50 degrees and unilateral hip dislocation; therefore both conditions should be treated operatively.