Current evidence suggests that impaired intestinal motility may facilitate gallstone formation by influencing biliary deoxycholate levels or by modulating interdigestive gall bladder motility (fig 2), although a primary intestinal defect in gallstone pathogenesis has not yet been demonstrated. In the cold war period, most interesting events, from a political point of view, occurred at the border between capitalist and communist systems, near the iron curtain. Similarly, the gall bladder and biliary tract can be viewed as the border between liver and intestinal tract, where many interesting things occur with profound impact on both systems. Combined efforts by researchers in the field of hepatology and gastrointestinal motility should brake down the Berlin wall of ignorance of one of the most common diseases in the Western world. (+info)
Pharmacological studies on root bark of mulberry tree (Morus alba L.)
Pharmacological studies were done on the root bark of mulberry tree and pharmacological effects were compared with the clinical effects of "Sohakuhi" in Chinese medicine. n-Butanol- and water-soluble fractions of mulberry root had similar effects except for those on the cadiovascular system. Both fractions showed cathartic, analgesic, diuretic, antitussive, antiedema, sedative, anticonvulsant, and hypotensive actions in mice, rats, guinea pigs and dogs. There appears to be a correlation between the experimental pharmacological results and the clinical applications of mulberry root found in the literature on Chinese medicine. (+info)
Retarded growth and deficits in the enteric and parasympathetic nervous system in mice lacking GFR alpha2, a functional neurturin receptor.
Glial cell line-derived neurotrophic factor (GDNF) and a related protein, neurturin (NTN), require a GPI-linked coreceptor, either GFR alpha1 or GFR alpha2, for signaling via the transmembrane Ret tyrosine kinase. We show that mice lacking functional GFR alpha2 coreceptor (Gfra2-/-) are viable and fertile but have dry eyes and grow poorly after weaning, presumably due to malnutrition. While the sympathetic innervation appeared normal, the parasympathetic cholinergic innervation was almost absent in the lacrimal and salivary glands and severely reduced in the small bowel. Neurite outgrowth and trophic effects of NTN at low concentrations were lacking in Gfra2-/- trigeminal neurons in vitro, whereas responses to GDNF were similar between the genotypes. Thus, GFR alpha2 is a physiological NTN receptor, essential for the development of specific postganglionic parasympathetic neurons. (+info)
Effects of duodenal distension on antropyloroduodenal pressures and perception are modified by hyperglycemia.
Marked hyperglycemia (blood glucose approximately 15 mmol/l) affects gastrointestinal motor function and modulates the perception of gastrointestinal sensations. The aims of this study were to evaluate the effects of mild hyperglycemia on the perception of, and motor responses to, duodenal distension. Paired studies were done in nine healthy volunteers, during euglycemia ( approximately 4 mmol/l) and mild hyperglycemia ( approximately 10 mmol/l), in randomized order, using a crossover design. Antropyloroduodenal pressures were recorded with a manometric, sleeve-side hole assembly, and proximal duodenal distensions were performed with a flaccid bag. Intrabag volumes were increased at 4-ml increments from 12 to 48 ml, each distension lasting for 2.5 min and separated by 10 min. Perception of the distensions and sensations of fullness, nausea, and hunger were evaluated. Perceptions of distension (P < 0.001) and fullness (P < 0.05) were greater and hunger less (P < 0.001) during hyperglycemia compared with euglycemia. Proximal duodenal distension stimulated pyloric tone (P < 0.01), isolated pyloric pressure waves (P < 0.01), and duodenal pressure waves (P < 0.01). Compared with euglycemia, hyperglycemia was associated with increases in pyloric tone (P < 0.001), the frequency (P < 0.05) and amplitude (P < 0.01) of isolated pyloric pressure waves, and the frequency of duodenal pressure waves (P < 0.001) in response to duodenal distension. Duodenal compliance was less (P < 0.05) during hyperglycemia compared with euglycemia, but this did not account for the effects of hyperglycemia on perception. We conclude that both the perception of, and stimulation of pyloric and duodenal pressures by, duodenal distension are increased by mild hyperglycemia. These observations are consistent with the concept that the blood glucose concentration plays a role in the regulation of gastrointestinal motility and sensation. (+info)
Regional effects of cholecystokinin octapeptide on colonic phasic and tonic motility in healthy humans.
The aim of this study was to assess in nine healthy subjects the effects of CCK octapeptide (CCK-8) on colonic tonic activity, measured by a barostat, and phasic activity, measured by manometry. On 2 consecutive days, recordings were performed in the unprepared proximal and distal colons during intravenous infusion of saline and CCK-8 at 5, 20, and 40 ng. kg-1. h-1. In the proximal colon CCK-8 induced, at the 20 and 40 ng. kg-1. h-1 doses, a tonic relaxation with an increase in barostat bag volume to 156 +/- 25 and 157 +/- 19% of basal (P < 0.01) and a decrease in phasic activity to 72 +/- 7 and 76 +/- 7% of basal (P < 0.01). In the distal colon, CCK-8 induced, at the 20 and 40 ng. kg-1. h-1 doses, a tonic relaxation (increase in intrabag volume to 133 +/- 12 and 149 +/- 15%, respectively; P < 0.01), whereas phasic activity increased (128 +/- 8 and 132 +/- 6%, respectively; P < 0.01). Effects of CCK-8 on tonic and phasic activities are different according to the colonic segment. Because meals induce colonic tonic contraction, our results suggest that CCK, as a hormone, is not an important mediator of the response of the colon to feeding in humans. (+info)
5-HT2B-receptor antagonist LY-272015 is antihypertensive in DOCA-salt-hypertensive rats.
We previously demonstrated a change in the receptors mediating 5-hydroxytryptamine (5-HT)-induced contraction in arteries of deoxycorticosterone acetate (DOCA)-salt-hypertensive rats. Specifically, contraction to 5-HT is mediated primarily by 5-HT2A receptors in arteries from normotensive sham rats and by both 5-HT2A and 5-HT2B receptors in arteries from hypertensive rats. We hypothesized that the 5-HT2B receptor may play a role in maintaining the high blood pressure of DOCA-salt-hypertensive rats, and herein we provide data connecting in vitro and in vivo findings. The endothelium-denuded isolated superior mesenteric artery of DOCA-salt rats displayed a marked increase in maximum contraction to the newly available 5-HT2B-receptor agonist BW-723C86 compared with that of arteries from sham rats, confirming that the 5-HT2B receptor plays a greater role in 5-HT-induced contraction in arteries from DOCA-salt rats. In chronically instrumented rats, the 5-HT2B-receptor antagonist LY-272015 (0.3, 1.0, and 3.0 mg/kg iv at 30-min intervals) was given cumulatively 1 time/wk during 4 wk of continued DOCA-salt treatment. LY-272015 did not reduce blood pressure of the sham-treated rats at any time or dose. However, LY-272015 (1.0 and 3. 0 mg/kg) significantly reduced mean blood pressure in a subgroup of week 3 (-20 mmHg) and week 4 DOCA-salt (-40 mmHg) rats that had extremely high blood pressure (mean arterial blood pressure approximately 200 mmHg). Blockade of 5-HT2B receptors by in vivo administration of LY-272015 (3.0 mg/kg) was verified by observing reduced 5-HT-induced contraction in rat stomach fundus, the tissue from which the 5-HT2B receptor was originally cloned. These data support the novel hypothesis that 5-HT2B-receptor expression is induced during the development of DOCA-salt hypertension and contributes to the maintenance of severe blood pressure elevations. (+info)
Erythromycin enhances early postoperative contractility of the denervated whole stomach as an esophageal substitute.
OBJECTIVE: To determine whether early postoperative administration of erythromycin accelerates the spontaneous motor recovery process after elevation of the denervated whole stomach up to the neck. SUMMARY BACKGROUND DATA: Spontaneous motor recovery after gastric denervation is a slow process that progressively takes place over years. METHODS: Erythromycin was administered as follows: continuous intravenous (i.v.) perfusion until postoperative day 10 in ten whole stomach (WS) patients at a dose of either 1 g (n = 5) or 2 g (n = 5) per day; oral intake at a dose of 1 g/day during 1.5 to 8 months after surgery in 11 WS patients, followed in 7 of them by discontinuation of the drug during 2 to 4 weeks. Gastric motility was assessed with intraluminal perfused catheters in these 21 patients, in 23 WS patients not receiving erythromycin, and in 11 healthy volunteers. A motility index was established by dividing the sum of the areas under the curves of >9 mmHg contractions by the time of recording. RESULTS: The motility index after IV or oral administration of erythromycin at and after surgery was significantly higher than that without erythromycin (i.v., 1 g: p = 0.0090; i.v., 2 g: p = 0.0090; oral, 1 g: p = 0.0017). It was similar to that in healthy volunteers (i.v., 1 g: p = 0.2818; oral, 1 g: p = 0.7179) and to that in WS patients with >3 years of follow-up who never received erythromycin (i.v., 1 g: p = 0.2206; oral, 1 g: p = 0.8326). The motility index after discontinuation of the drug was similar or superior to that recorded under medication in four patients who did not experience any modification of their alimentary comfort, whereas it dropped dramatically parallel to deterioration of the alimentary comfort in three patients. CONCLUSIONS: Early postoperative contractility of the denervated whole stomach pulled up to the neck under either i.v. or oral erythromycin is similar to that recovered spontaneously beyond 3 years of follow-up. In some patients, this booster effect persists after discontinuation of the drug. (+info)
The effect of motilin on the regulation mechanism of intestinal motility in conscious horses.
Laparotomy was performed on seven thoroughbreds to attach a force transducer to the proximal jejunum, distal jejunum, and ileum, as well as to the serous membrane of the cecum. Following observation of intestinal motility in conscious horses, they were intravenously injected with motilin (0.6 microgram/kg) to examine its effect on intestinal motility. Strong contractions peculiar to horses were observed in small intestine. Further, motilin caused strong contractions in the proximal jejunum. The results suggested the involvement of motilin in the regulation mechanism of intestinal motility. (+info)