Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024523 (malabsorption)
 7,319 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The pathology, aetiology and clinical features of cystic fibrosis (CF) are briefly reviewed. The diffuse endocrine system (DES) may be involved in either a primary or secondary manner. Carbohydrate intolerance is common and the release of islet hormones is deficient, as is the release of the intestinal hormone gastric inhibitory polypeptide (GIP). The post-prandial responses of insulin and GIP can be improved by substituting an elemental meal, suggesting that malabsorption and local intestinal factors could be causative in the deficient responses. Vasoactive intestinal polypeptide-like immunoreactive (VIP-LI) cell numbers are increased in CF and an intimate association with mucous cells is noted suggesting a paracrine relationship. These findings could have implications in the diagnosis, management and aetiology of CF.
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PMID:The diffuse endocrine system in cystic fibrosis. 635 16

Piglet cryptosporidiosis is characterized by intestinal villous damage and malabsorption and by reduced NaCl absorption in response to prostaglandin (PG) release from inflamed tissue. We hypothesized that the PG effect is mediated by the enteric nervous system. Piglets were infected with cryptosporidium and ileal mucosa was studied in Ussing chambers. Studies with tetrodotoxin and indomethacin showed that 75% of the PG-induced alteration in NaCl transport was mediated by the enteric nervous system. Prostacyclin was elevated in infected tissue, and its analog, carbacyclin, mimicked the altered transport response in indomethacin-treated tissue. This carbacyclin response was abolished by tetrodotoxin. The vasoactive intestinal peptide (VIP) receptor antagonist, VIP-10-28, and the muscarinic antagonist, atropine, individually reduced and together abolished the response to carbacyclin, whereas the nicotinic blocker, hexamethonium, reduced the carbacyclin response by 75%. The somatostatin analog, octreotide, and the a-2 adrenergic agonist, clonidine, each abolished the carbacyclin response and partially or completely rectified the altered NaCl transport of the infection. These results indicate that PGs alter NaCl transport in this infection primarily by stimulating cholinergic interneurons that innervate VIPergic and cholinergic motor nerves. The enteric nervous system may be a potential target for pharmacological control of the acute diarrhea in this infection.
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PMID:Role of the enteric nervous system in piglet cryptosporidiosis. 896 31

Intestinal secretion is a normal phenomenon, indispensible to solubilize and dilute nutrients and to maintain fluidity in the intestinal lumen. Enterotoxins and certain drugs may disrupt the proabsorptive status maintained by the small intestine under physiologic conditions. Hormones found in nervous and specialized intestinal enterochromaffin cells are responsible, in part, for secretion of fluid into the lumen. Afferent vagal nerve impulses mediated by 5-hydroxytryptamine (serotonin; 5-HT), vasoactive intestinal peptide (VIP) and substance P are the major agents of secretory stimulation. Toxins from pathogenic bacteria, especially some strains of E. coli and V. cholerae, trigger a secretory response and a chain of events involving cGMP and cAMP which result in chloride secretion, coupled to sodium and fluid efflux into the lumen. If secretion is unchecked by natural mechanisms or medications, the consequences are diarrhea, with potential dehydration, hyponatremia and ultimately death. Introduction of absorbable nutrients in the intestinal lumen has a major antisecretory action, both by a nutrient-gene interaction and by proabsorptive hormone expression. In additon, during the absorptive process water is carried into the enterocyte together with solutes. Hydrolysis-resistant peptides of dietary origin and ingested soluble fiber may also have a proabsorptive effect. The gastrointestinal system has a variety of antisecretory or proabsorptive hormonal and protein agonists that balance the outflow of fluid and electrolytes. The more extensively studied are neuropeptide Y/peptide YY (NPY/PYY) and the antisecretory factor (AF). Nitric oxide (NO), a short-lived second messenger, has a major role in secretion by activating cGMP. The intracellular concentration of NO may regulate the absorptive/secretory status of the small intestine, either stimulating absorption or inducing secretion. Specifically targeted 5-HT receptor antagonist drugs and other pharmacologic agents have been clinically tried for the treatment of severe diarrhea, drug-induced malabsorption and reversal of cellular damage.
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PMID:Regulation mechanisms of intestinal secretion: implications in nutrient absorption. 1198 1