Phytate is the major storage form ofphosphorus in seeds and so is a common dietary constituent. Excessive ingestion of undegraded phytates can cause mineral deficiencies in humans. In addition, phytic acid is antineoplastic in animal models of both colon and breast carcinoma. There have been no previous studies quantifying phytase activity in the human small intestine although it is present in animals. Small intestinal phytase and alkaline phosphatase activity and distribution was measured in vitro in mucosal homogenates from two human small intestinal specimens obtained from transplant donors. Rat intestine was also studied for comparison. Phytase activity was found in human small intestine at low values (30 times less than that in rat tissue and 1000-fold lower than alkaline phosphatase in the same tissue). The activity was greatest in the duodenum and lowest in the ileum. In conclusion, the normal human small intestine has very limited ability to digest undegraded phytates. Although this may have adverse nutritional consequences with respect to metabolic cation imbalances, the presence of undigested phytate in the colon may protect against the development of colonic carcinoma.

Summary and conclusionsThe 14C-aminopyrine ('4C-amidopyrine)

SUmmARY Copper in bile has been shown by electrophoresis to occur neither as free ions nor complexed to protein but to be associated with a component of the micellar complexes of bile. Solvent fractionation studies suggest that the bile salt components of the lecithin-bile salt complexes are the active binding agents. The effects of specific bile salts on the behaviour of copper during electrophoresis supports this possibility.The relationship of certain bile salts to the excretion of copper in man during the time that an external biliary fistula was functioning and to the intestinal absorption of copper in the rat was found to confirm this concept.

Background/Aims-Asymptomatic resi-

To date, tests of small intestinal passive permeability have involved the ingestion of test molecules whose permeation is assessed indirectly by measuring their urinary recovery. Excretion ratios of marker molecules (eg, lactulose-to-mannitol excretion ratio, LMER) are useful clinically. Measurement of permeability markers in serum would improve the convenience of the tests. Our aim was to assess small intestinal permeability in celiac patients using serum lactulose and mannitol levels with calculation of lactulose to mannitol serum ratios (LMSR) and to compare the results with the standard methods using urinary recoveries. Twenty-four newly diagnosed celiacs and 10 control subjects were studied; 10 celiacs were restudied while established on a gluten-free diet. Test subjects and patients ingested 10 g lactulose and 2.5 g mannitol in 50 ml water. In 10 untreated celiacs and the controls, blood was taken from 0 to 120 min and all urine was collected for 6 hr. The remaining 14 untreated and the 10 treated celiacs had a single serum sample taken 60 min after ingestion of the test solution. At 1 hr after ingestion, the mean mannitol level in normals (0.156 mmol/liter) was significantly higher than in untreated celiacs (0.06 mmol/liter). The 1-hr mean serum lactulose level in normals (0.125 micromol/liter) was significantly lower than in untreated celiacs (0.56 micromol/liter). The median 1-hr LMSR in untreated celiacs was 0.42 compared with 0.039 in normals and 0.08 in treated celiacs. There was a significant correlation between LMSR and LMER. Permeability testing using serum measurements of lactulose and mannitol gave comparable results in celiac patients to the tests using urinary recovery of the permeability markers and may prove to be more convenient, especially in pediatric patients.