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H Menge

Publications and source records attributed to H Menge.

At least 91 records · Page 5Linked to original sources

Functional and structural characteristics of the rat intestinal mucosa following ileo-jejunal transposition.

The transformation of the rat ileal mucosa following interposition into the jejunum has been examined with respect to its functional and structural characteristics. Morphometric studies show that there is an increase in the size of the villi and crypts in the same proportions, such that the structures become longer than those of normal jejunal mucosa. There is no change in villus width or epithelial cell height and no evidence of mucosal damage. In agreement with these observations, there is an increase in the amount of DNA per unit weight mucosa in the transposed ileum. L-phenylalanine accumulation in vitro by transposed loops is reduced to the level of the control jejunum, whereas beta-methyl-D-glucose uptake is unchanged. Biochemical and histochemical determinations of various enzyme activities reveal that the levels in the transposed mucosa are much lower than in the controls. The results show that although certain features of the transposed ileum resemble those of the normal jejunum, this does not apply to all characteristics. It is argued that the ileal mucosa retains its normal functional properties, but undergoes hyperplastic changes, possibly as a result of contact with chyme that is richer in nutritive material, resulting in the establishment of a more immature cell population with a global reduction in enzyme levels and transport capacities.

Animals↗

Structural and functional studies on the transformation of the intestinal mucosa in rats with experimental diabetes.

Twenty days after the onset of alloxan-induced diabetes, a villous hyperplasia has developed in the intestines of rats having free access to food. The transformation is characterised by a considerable increase in the area of the villous surface, caused by an enhanced mitotic activity in the crypts. The absorption of glucose or methionine by jejunal loops, whether expressed in terms of serosal area or villous area, is unchanged at this stage. On the other hand, the specific activity of certain disaccharidases and dipeptidases in crude mucosal homogenates is greater in diabetic animals, but quantitative histochemistry revealed no changes in the activities of alkaline phosphatase, leucine amino-peptidase and non-specific esterase in the individual enterocytes. Thus the biochemical changes may simply reflect the hyperplasia of the mucosa. The blood sugar level does not appear to be directly responsible for the mucosal transformation; however, the positive correlation between the daily food intake and the villus height suggests a role of hyperphagia and consequent increased luminal nutrition in the development of the hyperplasia.

Animals↗

[Functional and morphological studies on intestinal mucosa of the rat under chronic glucagon application (author's transl)].

Chronic application (20 days) of glucagon in pharmacological doses induces mucosal transformation of the hyperregenerative type in the small intestine of the rat. This transformation is characterized by decreased villi, and increased crypt length. The morphological changes are accompanied by a reduction in glucose absorption in vivo as well as by decreased activities of lactase, sucrase and maltase. The findings demonstrate that hyperglucagonemia is not the cause for hyperplastic mucosal transformation, which is found in the experimental diabetes in the rat.

Animals↗

Functional and structural characteristics of the jejunum and ileum in the dog and the rat.

The dog jejunum is a much denser tissue than the ileum, with a greater weight per unit length and higher proportion of mucosal tissue. Morphometric analysis reveals longer and wider villi, deeper crypts and larger enterocytes in the jejunal mucosa. Uptake of phenylalanine or beta-methyl-glucoside by tissue slices in vitro is slightly greater in jejunal than in ileal tissue. The levels of acid phosphatase and alkaline phosphatase in the individual enterocytes are significantly greater in the jejunum, according to quantitative histochemical analysis. The absorption of water, sodium, potassium, chloride and glucose in vivo is significantly smaller in the jejunal than in ileal loops, particularly when expressed in terms of unit mucosal weight. Sodium and water absorptions are stimulated by glucose at both sites, but the stimulation is significantly greater in the ileum. Opposite results have been obtained in rats where the transport of phenylalannie in vitro is greater in the ileum, but water, electrolyte and glucose absorption in vivo is greater in the jejunum.

Acid Phosphatase↗

Enhanced non-electrolyte uptake in vitro by the dog jejunal mucosa in the cholera-toxin-induced secretory phase.

A characteristic secretory response in the dog jejunumis observed following three hours' perfusion with cholera toxin. When this mucosa in the secretory phase is examined in vitro, the steady-state accumulation of phenylalanine and beta-methyl-glucoside is considerably enhanced. Since the initial rates of influx of these substrates are unchanged and the tissue ion contents are the same as normal, it is concluded that the increase in steady-state uptake may be attributed to a change in the rate of efflux of the substrates across the baso-lateral membrane of the cell. This change might be related to the reported collapse of the intercellular channels when the intestine is in a secretory state.

Animals↗

[Alpha-chain disease presenting as malabsorption syndrome with exudative enteropathy (author's transl)].

A 30-year-old Turk was admitted with signs of exudative enteropathy together with malabsorption. There was no improvement on a gluten-free diet. Immunological investigations demonstrated atypical IgA-immunoglobulin in the serum which did not precipitate with antisera against L-chains. Peroral ileal biopsy and surgical biopsy material showed a diffuse proliferation of plasma cells in an altered ileal mucosa and in the mesenteric lymph nodes. Skeletal X-rays showed no osteolysis and the bone marrow showed no evidence for multiple myeloma. Treatment with melphalan and steroids resulted in a three year remission. In the terminal stage an intra-abdominal malignant lymphoma developed.

Adrenal Cortex Hormones↗

The consequences of ischaemia after mechanical obstruction of the dog ileum.

A mechanical obstruction was produced in the dog ileum, and four days later, loop of intestine above and below the occlusion were subjected to one hour's ischaemia. This led to widespread morphological and functional damage of the epithelium, indistinguishable from the response of the normal intestine. The recovery of the mucosa of both loops after the ischaemia followed exactly the same pattern as when there was no occlusion superimposed: The transport capacity for phenylalanine in vitro was entirely restored, whereas that of beta-methyl-glucoside, together with oxygen consumption and lactate production, remained depressed; morphometric examination revealed that the recuperating mucosa had smaller villi, shorter crypts and smaller epithelial cells than the contiguous untouched tissue. These results suggest that the regenerative potential of the crypts could not be obliterated by one hour's ischaemia, either in the presence of a noxious obstruction fluid above the occlusion, or in the atrophic mucosa below it.

Acid Phosphatase↗

The functional response of the dog ileum to one hour's ischaemia.

1. The function and structure of dog ileal mucosa was examined immediately after arterial ischaemia for 1 h and 1, 3 or 7 days after the trauma. 2. Immediately after the ischaemia, there was a net movement of water and ions into a luminal perfusate in vivo. One day later, there was no net movement of water and electrolytes but net absorption returned on the third day. 3. Active transport of phenylalanine or beta-methylglucoside by mucosal strips in vitro was abolished immediately after the trauma but was largely restored 1 day later. There was a close correlation between glucose absorption in vivo and beta-methylglucoside uptake in vitro. 4. Morphological study revealed pronounced desquamation of enterocytes immediately after the trauma. The regenerating mucosa had shorter villi and crypts, and lower enzyme activities assessed histochemically 1 day later. Most parameters had returned to normal by the third post-operative day.

Acid Phosphatase↗

Morphology and function of the dog ileum after mechanical occlusion.

1. Complete mechanical occlusion of the ileum was produced in dogs and the loops above and below the obstruction were examined functionally and morphologically 4 or 7 days later. 2. The intraluminal pressure in the occluded loop never exceeded 8 cm water. 3. The mucosa above the obstruction secreted water and ions into the lumen in vivo, though it absorbed glucose normally. Mucosal slices also absorbed amino acids and monosaccharides normally in vitro. 4. The mucosa below the obstruction absorbed ions and glucose in vivo and non-electrolytes in vitro to a slightly smaller extent than normal intestine. 5. The morphological changes above the occlusion included shorter, plumper villi and shorter crypts, a reduction in histochemically stainable brush-border enzymes, but an increase in acid phosphatase. Below the obstruction, there was atrophy of the villi and crypts and reductions in all enzymes studied. 6. The results suggest that the mucosa above the occlusion possesses an intact and almost normal epithelial layer, but that it has been stimulated to secrete in vivo, presumably by intraluminal factors. Below the obstruction, true atrophy of the mucosa has promptly developed.

Acid Phosphatase↗