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Small bowel neomucosa has been grown on a variety of surfaces. The purpose of this study was to compare the rate of growth and function of neomucosa on colon serosa (CS) and abdominal wall muscle (AM) in New Zealand white rabbits. The terminal ileum was incised for 5 cm and patched with either adjacent CS (23 animals) or AM (19 animals) to create a 2 X 5-cm defect. Gross and histologic examinations of the specimens at 1, 2, 4, and 8 weeks revealed that the rate of growth was similar in both groups. There was minimal lateral ingrowth at 2 weeks, nearly complete coverage of the defects at 4 weeks, and complete coverage of the defect at 8 weeks in more than 85% of animals with mature villi and muscularis mucosae. The ileal diameter at the site of patching increased in both groups from 11.9 +/- 2.6 to 16.3 +/- 3.2 mm in the CS group and 11.3 +/- 2.5 to 15.1 +/- 1.8 mm in the AM group (P less than 0.01). Glucose uptake was similar in both groups being 65.4 +/- 24.1% of control in the CS group and 73.9 +/- 29.8% in the AM group. Brush border enzyme activity of sucrase, maltase, and lactase was similar to controls in the AM group but in the CS group activity of sucrase and maltase were significantly less than controls (P less than 0.01). Average body weight was increased postoperatively in both groups. There was one anastomotic leak in each group and two cases of partial intestinal obstruction in the abdominal wall group.(ABSTRACT TRUNCATED AT 250 WORDS)

Growing intestinal neomucosa in patched intestinal defects has been investigated as a means of permanently increasing the absorptive capacity in the short bowel syndrome. Several factors, including luminal contents, appear to affect the growth and function of the neomucosa. The purpose of this study was to compare function and rate of growth of neomucosa in patched defects of the jejunum and ileum. In both the jejunum and ileum of 11 New Zealand white male rabbits 2 X 5-cm patched intestinal defects were created using the serosal surface of adjacent colon. The animals were sacrificed at 4 weeks (n = 6) and 8 weeks (n = 5) after operation. Grossly there was more complete coverage of the defect by neomucosa in the ileum at both 4 and 8 weeks (99.1 +/- 1.1% vs 92.6 +/- 6.3% overall P less than 0.005). Villous height of the ileal neomucosa was similar to normal mucosa at 8 weeks (209 +/- 21 vs 244 +/- 18 m) but was significantly less in the jejunum (209 +/- 16 vs 273 +/- 16 m, P less than 0.005). Glucose uptake by neomucosa was greater in the ileum than the jejunum (3.34 +/- .84 vs 2.39 +/- .46 nmole/min/mg, P less than 0.05) but was similar to normal mucosa at both sites. Disaccharidase activity (lactase, sucrase, and maltase) was similar in both jejunum and ileum but was significantly less in ileal neomucosa than in normal mucosa (P less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of taxol, a potent stabilizer of microtubules, on plasma protein secretion by slices prepared from mature and developing rat liver was determined. After 4 hr of incubation, taxol (50 microM) inhibited albumin secretion by only 10% on gestation Day 19, by 16% 4 days after birth, but by 40% in the adult. Inhibition of glycoprotein secretion by taxol was similar to that of albumin secretion at all ages studied. Combined with information obtained from previous investigations, the present study indicates that agents that either inhibit microtubular assembly or that stabilize microtubules both have a reduced capacity to inhibit hepatic protein secretion during development. These findings suggest that a reduced requirement for microtubular participation in protein secretion is present in developing liver.

The short bowel syndrome is a potential complication of the surgical management of diseases of the large and small intestine. Recently methods have been examined for expanding the small bowel absorptive area using prosthetic materials. We investigated the feasibility of growing intestinal mucosa on prosthetic patches and tubes. Ileal defects were patched with a 2 X 5-cm patch of either Dacron (n = 15), polyglycolic acid mesh (PGA) (n = 9), or polytetrafluroethylene (PTFE) (n = 5) prosthesis in New Zealand white male rabbits. Gross and microscopic analysis at 2, 4, and 8 weeks revealed that the serosal surface was covered with neomucosa by 4 weeks. Dacron and PTFE grafts were either minimally attached or extruded and PGA grafts had dissolved. At 8 weeks, none of the patches were present but with all three materials the resultant area of neomucosa was only 15% of the original defect. The neomucosa was functional as determined by glucose uptake and disaccharidase activity. Three centimeter Dacron tubes were interposed in the distal ileum of 10 rabbits and in a bypassed ileal segment in 11 rabbits. There was an 80% mortality within 2 weeks, and no evidence of neomucosal growth. Although prosthetic patches support the growth of functional neomucosa, there is a minimal increase in the final surface area. The type of prosthesis did not influence the outcome. The use of Dacron tubes is associated with high mortality and no neomucosal growth. The use of prosthetic materials is not likely to be useful in the clinical management of the short bowel syndrome.

Growing neomucosa on patched intestinal defects has been investigated as a method of expanding the intestinal absorptive area. The purpose of this study was to determine the effect of luminal factors on the rate of growth and function of neomucosa in rabbit ileum. A 2 X 5-cm distal ileal defect was patched with adjacent colon serosa in 10 New Zealand white male rabbits. A similar defect was patched in a bypassed ileal segment in an additional 10 rabbits. Five animals in each group were sacrificed at 4 and 8 weeks for determination of the gross and microscopic growth of neomucosa, glucose uptake, and disaccharidase activity. In addition, tritiated thymidine uptake was measured in neomucosa and incontinuity ileum at the 4-week sacrifice. Grossly, the patched defects were covered in nearly all animals by 4 weeks and coverage was complete at 8 weeks. Microscopically, the mucosa was less well developed in the bypassed group with a mean villous height significantly less than the incontinuity group (139.9 +/- 13.9 microns vs 212.33 +/- 30.3 microns, P less than 0.0005). In vitro uptake of [3H]thymidine was significantly higher in neomucosa in bypassed segments when compared with neomucosa in incontinuity segments (692.5 +/- 347.8 vs 278.0 +/- 134.8, P less than .05, expressed as percentage of normal incontinuity ileum). Glucose uptake was similar in both groups but disaccharidase activity was significantly less in the bypassed group. The increased uptake of [3H]thymidine in neomucosa in the bypassed segment may reflect the histologic immaturity of this tissue with a greater proportion of DNA synthesizing cells.(ABSTRACT TRUNCATED AT 250 WORDS)