Ultrastructural Changes in Cells of the Gastric and Small Intestinal Mucosa during Bronchial Asthma

Abstract

The complex of structural changes in the gastroduodenal mucosa in patients with bronchial asthma is considered as a polyetiological primary degenerative process with progressive atrophy of the epithelium and formation of erosions. Ultrastructural signs included degenerative changes in the endothelium of microvessels and surface and glandular epithelium, which were accompanied by compensatory hyperfunction of intact mucus-producing cells, hyperplasia, and increased functional activity of mast and immunocompetent cells. The development of destructive and erosive lesions was associated with hyperplasia of parietal and endocrine cells in the mucosa. We evaluated the specific structural reactions clinically typical of bronchial asthma of different severity. The data are interpreted in terms of a relationship between pathological changes in the mucosa of different localization.

The impact of asthma on the gastrointestinal tract (GIT)

“…Additionally, the intestinal lamina propria has shown increased mast cell infiltration 5,7. This infiltration of lymphocytes and mononuclear cells into the lamina propria does not differ between allergic and non-allergic asthmatics although treatment has been seen to induce an effect.…”

“…Severe to moderate asthmatics possess mucin granules with an electron transparent nature when viewed under a TEM while mild to moderate asthmatics’ mucin granules possess a osmophilic nature 7. Moderate to severe asthmatics hold a large number of mixt-cells, in possession of a large number of mucin granules, within their fundal glands.…”

“…Numerous vasoactive biomolecules have been identified as possible candidates for these hemodynamic alterations within the respiratory tissues of asthmatics, including histamine, interleukin-8 (IL-8), and, of particular importance in facilitating angiogenesis, vascular endothelial growth factor (VEGF) 11,14,15. Hemodynamic alterations, primarily within in the gastric folds where the endothelium reveals a heterogeneous structure, have been reported amongst asthmatics 7. Further research is required to determine whether or not these stomach hemodynamic alterations are facilitated by the same vasoactive biomolecules as in the respiratory systems of asthmatics.…”

“…Moderate to severe asthmatics hold a large number of mixt-cells, in possession of a large number of mucin granules, within their fundal glands. The occurrence of these mixt-cells may either be the result of delayed glandular differentiation or the inhibition of protein synthesis due to stomach degeneration and emergency compensation through increased mucus production 7. In the pylorus, on the other hand, surface epithelium cells possess round, electron dense granules and, within moderate asthmatics, hyperplasia of its endocrine cells 7…”

“…This process can affect the structure of the airways through the secretions of various growth factors, inflammatory molecules and ECM elements by the myofibroblasts themselves 12. Moderate diffuse fibrosis may be present within the small intestine of asthmatics 7. Its presence is understandable in the GIT as fibrosis commonly occurs in response to inflammation, which would appear to be present in the GIT of asthmatics due the feature of increased leukocyte influx, and may even contribute to furthering this inflammatory state 32,33…”