Gastrointestinal tract motility

Colonic residence time as dictated by gastrointestinal tract motility... 

Lower gastrointestinal tract motility regulators trimebutine maleate... 

Mentha arvensis L. M. haplocalyx Briq. China Menthol, menthone, menthyl acetate.33 Stimulate gastrointestinal tract motility and central nervous system, dilate peripheral blood vessels. Increase sweat gland secretion. 

For almost one century, acetylcholine has been recognized as a neurotransmitter both in the central nervous system and the peripheral nervous system. In the peripheral nervous system, acetylcholine has been identified as the neurotransmitter of autonomic ganglia and the neuromuscular junction. Acetylcholine is involved in different peripheral functions such as heart rate, blood flow, gastrointestinal tract motility, and sweat production and smooth muscle activity. In the CNS, cholinergic neurotransmission plays a crucial role in a variety of CNS functions including sensory perception, motor function, cognitive processing, memory, arousal, attention, sleep, nociception, motivation, reward, mood, and psychosis. 

Table 1 Factors affecting drug absorption from the colon Physical characteristics of drug (pkTa> degree of ionization) Colonic residence time as dictated by gastrointestinal tract motility...

B. Octreotide also suppresses pancreatic function, gastric acid secretion, and biliary and gastrointestinal tract motility. 

The activity of Enteroplant (twice daily) was compared to that of cisapride (30 mg daily), a serotonin 5-HT4 agonist that stimulates upper gastrointestinal tract motility, over a 4-week period. This double-blind, randomized trial found that both products had comparable ef cacy in terms of pain severity and frequency. Dyspeptic Discomfort Score, and Clinical Global Impressions (Madisch et al., 1999). 

The activity of Enteroplant (twice daily) was compared with that of cisapride (30 mg daily), a serotonin 5-HT4 agonist that stimulates upper gastrointestinal tract motility, over a 4-week period. 

A not uncommon side effect observed with morphine and some of the other narcotic analgesics is constipation due to decreased motility of the gastrointestinal tract. It proved possible to so modify pethidine as to retain the side effect at the expense of analgesic activity. Relief of diarrhea, it will be realized, is a far from trivial indication. Alkylation of the anion from diphenylacetonitrile (95) with ethylene dibromide gives the intermediate, 96. Alkylation of normeperidine (81) with that halide... 

A high concentration of DOPs is found in the olfactory bulb, the neocortex, caudate putamen, and in the spinal cord, but they are also present in the gastrointestinal tract and other peripheral tissues. The functional roles of DOP are less clearly established than for MOP they may have a role in analgesia, gastrointestinal motility, mood and behaviour as well as in cardiovascular regulation [2]. 

Vasoconstriction of peripheral blood vessels Regulates release of neurotransmitters decreases tone, motility, and secretions of gastrointestinal tract Increased heart rate, increased force of myocardial contraction... 

Gastrointestinal tract-decrease in secretions of the stomach, decrease in gastric and intestinal movement (motility)... 

There are a number of side-effects of opiates that are due to their actions on opiate receptors outside the central nervous system. Opiates constrict the pupils by acting on the oculomotor nucleus and cause constipation by activating a maintained contraction of the smooth muscle of the gut which reduces motility. This diminished propulsion coupled with opiates reducing secretion in the gut underlie the anti-diarrhoeal effect. Opiates contract sphincters throughout the gastrointestinal tract. Although these effects are predominantly peripheral in origin there are central contributions as well. Morphine can also release histamine from mast cells and this can produce irritation and broncho-spasm in extreme cases. Opiates have minimal cardiovascular effects at therapeutic doses. 

NW Weisbrodt. Motility of the small intestine. In LR Johnson, ed. Physiology of the Gastrointestinal Tract. New York Raven Press, 1989, pp 631-664. 

A summary of how physiological factors affect the dissolution rate is given in Table 21.2. The effective surface area will be affected by the wetting properties of the bile acids and other surface-active agents in the gastrointestinal tract. The dif-fusivity of a drug molecule in the intestinal juice will be altered by changes in viscosity that are induced, for instance, by meal components. An increased dissolution rate could be obtained at more intense intestinal motility patterns or increased... 

The absence of Gram-negative bacilli is a reliable and valid indication of preserved intestinal clearance, which precludes a significant failure of intestinal motility and anatomical abnormalities inducing stasis or recycling of contents from the lower gastrointestinal tract. 

Anuras S Motility Disorders of the Gastrointestinal Tract. New York, Raven Press, 1992. 

Boseman T, Anuras S, Hutton E, Ghandour E, Mikeska C Abnormal motility of the upper gastrointestinal tract in Parkinson s disease. Am J Gastroenterol 1990 85 1264A. 

In the periphery, 5-HT4 receptor mRNA is found in vascular smooth muscle. Newly developed drugs that activate 5-HT4 receptors are of interest for their potential in treating cardiac arrhythmia. The 5-HT4 receptor is also located on neurons of the alimentary tract, for example the myenteric plexus of the ileum, and on smooth muscle cells and secretory cells of the gastrointestinal tract, where they evoke secretions and the peristaltic reflex. 5-HT4 receptor agonists (e.g. cisapride, prucalopride, tegaserod) are used therapeutically in the treatment of constipation-predominant irritable bowel syndrome and in functional motility disorders of the upper gastrointestinal tract. 

The physiological changes and other aspects in the elderly makes this even more complicated. Example of this is decreased stomach acidity decreased motility decreased blood-flow to liver and gastrointestinal tract changed pharmacokinetics and -dynamics polypharmacy swallowing problems bad nutritional status and lack of documentation. 

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