Intestinal lumen exposed

Two case studies of acute intrusion of barium sulfate into the peritoneal space during barium enema examination of four men showed barium sulfate caused an acute inflammatory tissue response (Kay 1954 Yamamura et al. 1985), and in one case resulted in formation of a fibrous granuloma (Kay 1954). This is an extremely rare mode of entry and not of significant concern for individuals exposed at a hazardous waste site. Increased fluid accumulation in the intestinal lumen of rats was observed after intraperitoneal injection of barium chloride (Hardcastle et al. 1983b, 1985) however, this observation is not significant for individuals exposed at hazardous waste sites because of the route of exposure and because there has been no documentation of this effect occurring in humans following normal exposure routes. 

The other principal lysosomal enzyme of relevance is DNase II. This is a ubiquitous DNase found in the lysosomes of all tissues that functions at an acidic pH in the absence of metal ions. DNase II is considered to be a barrier to the transfection of cells by potentially therapeutic gene sequences (Howell et al. 2003) any oligonucleotides delivered to cells for therapeutic reasons are highly likely to be endocytosed and end up in lysosomes and exposed to DNase. Given its acid pH optimum, whether DNase II would be very active in the lumen of the intestine following the sloughing-off of enterocytes is not certain. 

In addition to cholesterol present in the lumen, the intestinal epithelial cells are also exposed on their basal-lateral surfaces to cholesterol carried in circulating lipoproteins. It is of interest, therefore, to determine if variations in this source of... 

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