Mosapride citrate (Mosapride) is a new prokinetic agent that enhances the gastrointestinal (GI) motility by stimulation of 5-HT4 receptors. This agent stimulates acetylcholine release from enteric cholinergic neurons in the GI wall. It was reported in several studies that mosapride selectively enhanced the upper, but not lower, GI motor activity. However, in these studies other 5-HT4 receptor agonists exerted stimulating effects on the motility of the colon. Moreover, it is well known that the receptors of 5-HT4 are also located in the colon. The purpose of this study was to estimate the effect of mosapride on the motility of the stomach, ileum and colon in the guinea pig and to investigate whether or not mosapride influenced the colonic motility. Mosapride significantly increased the amplitude of the contraction waves in the guinea pig stomach by electrical stimulation. In addition, it significantly increased the number of peaks, the area under the curve and the propagation velocity of the peristaltic contraction of the guinea pig ileum in a concentration dependent fashion. Mosapride also significantly shortened the transit time of the guinea pig colon. Accordingly, we concluded that mosapride exerted prokinetic effect on the entire GI tract of the guinea pig. Based on the possibility of similar results in humans, we suggest the potential use of mosapride for lower GI motor disorders such as constipation and upper GI motor disorders such as gastroesophageal reflex disease or gastroparesis.
Animals ; Benzamides/*pharmacology ; Colon/*drug effects ; Gastrointestinal Agents/*pharmacology ; Gastrointestinal Motility/*drug effects ; Guinea Pigs ; Ileum/*drug effects ; Morpholines/*pharmacology ; Stomach/*drug effects ; Support, Non-U.S. Gov't

OBJECTIVETo investigate the characteristic of colonic transmission in functional constipation (FC) and the effect of traditional Chinese medicine (TCM) Sini Powder (SP) on it.

METHODSThe colonic transmission time (CTT) of 36 patients with FC (the FC group) and 22 healthy subjects (control group) was measured through colonic transmission test, and CTT of entire colon and that of various subsections was calculated with Hinton method and Arhan method respectively. After then, the FC group was treated with SP for 7 days, and CTT was detected again after treatment.

RESULTSBefore treatment, body mass index (BMI) was higher, CTT of entire colon, left half colonic section, and sigmoid-rectal section were longer in the FC group than those in the control group (P < 0.05), no statistical difference in CTT of right half colon was found between the two groups (P > 0.05). After FC patients being treated with SP, their CTT of whole colon, left half colonic section and sigmoid-rectal section were significantly shortened (P < 0.05).

CONCLUSIONFC patients were characterized by increased BMI and CTT prolonged and unevenly distributed in subsections, especially in the left half colon, sigmoid and rectum; SP could shorten the CTT in FC patients.

Adult ; Body Mass Index ; Colon ; drug effects ; physiopathology ; Colon, Sigmoid ; drug effects ; physiopathology ; Constipation ; drug therapy ; physiopathology ; Drugs, Chinese Herbal ; therapeutic use ; Female ; Gastrointestinal Transit ; drug effects ; Humans ; Male ; Middle Aged ; Phytotherapy ; Time Factors ; Treatment Outcome

OBJECTIVETo induce DNA oxidative damage in colorectal crypt cells by hydrogen peroxide in vitro.

METHODSHydrogen peroxide was diluted into 100, 50, 10, 5 and 1 micromol/L with RPMI 1640. Colorectal crypt cells were treated with peroxide for 10 min, 30 min, 1 h, 1.5 h, 12 h and 24 h respectively. The survival of colorectal crypt cell was measured by MTT method, and the DNA oxidative damage special product, 8-OhdG was detected with immunohistochemical staining. Liner regression was used to measure the time trend of survival rate with SPSS 10.0 software.

RESULTSurvival rate of colorectal crypt cell was 60% and 80% after 10 min of hydrogen peroxide treatment. The longer treatment of hydrogen peroxide, the lower survival rate; the survival rate was reduced to 30% in 24 h. After 10 or 30 min treatment of 100 or 50 micromol/L hydrogen peroxide, the survival rates of colorectal crypt cells were reduced by 20% compared with those of 10, 5 and 1 micromol/L hydrogen peroxide. However, while cells were treated with different concentrations of hydrogen peroxide for 1.0 h or above, there were no differences in cell survival rates. The time trend test results demonstrated that the survival rates of colorectal crypt cells treated with 10, 5 and 1 micromol/L hydrogen peroxide were significantly decreased with the time length of treatment. Colorectal crypt cells treated with different concentrations of hydrogen peroxide for 15 minutes were positively stained brown in cytoplasm and nuclear by immunohistochemistry with 8-OhdG monoclonal antibody.

CONCLUSIONHydrogen peroxide could induce DNA oxidative damage in colorectal crypt cells. And treated with 1 - 10 micromol/L hydrogen peroxide for 10 - 30 min, DNA oxidative damage is apt to be induced in colorectal crypt cell.

Carbazoles ; analysis ; Cells, Cultured ; Colon ; cytology ; drug effects ; metabolism ; Humans ; Hydrogen Peroxide ; Models, Biological ; Oxidative Stress ; drug effects ; Propanolamines ; analysis ; Stem Cells ; cytology ; drug effects

Chronic kidney disease (CKD) has become a worldwide health and social problem. Retarding its progression to end-stage renal disease is beneficial both to the patients and the healthcare system. Plenty of clinical trials have indicated that enema with Chinese medicine could effectively prevent chronic renal failure, and was widely used in the clinical practice. However, studies on mechanism were still nearly blank, which may prevent further improvement of therapeutic efficacy. Recent studies had discovered that colon was an important organ where uremic toxins were generated. The uremic toxins involved could not only promote CKD progression, but also was closely correlated with CKD mortality. Reducing production and promoting excretion of toxins were confirmed to reduce renal tubule interstitial fibrosis and delay renal progression. On the basis of the theory of gut-kidney axis above, we had conducted pilot clinical researches to evaluate the effect of enema with Chinese medicine on the intestinal flora, gut barrier, enterogenous uremic toxins and renal protection. The preliminary results revealed that rheum enema through colon could accelerate intestinal dynamics, improve intestinal barrier function, regulate intestinal flora and reduce production and absorption of intestine-derived uremic toxins such as indoxyl sulfate, which may reduce renal fibrosis and delay renal progression. Further studies could provide more evidence for colon as a new therapeutic target for the treatment of CKD with Chinese medicine.
Colon ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Enema ; Humans ; Kidney ; drug effects ; pathology ; Renal Insufficiency, Chronic ; drug therapy ; pathology ; Treatment Outcome

Effective drug to manage constipation has been unsatisfactory. We sought to determine whether methionine has effect on the human colon. Human colon tissues were obtained from the specimens of colon resection. Microelectrode recording was performed and contractile activity of muscle strips and the propagation of the contractions in the colon segment were measured. At 10 microM, methionine depolarized the resting membrane potential (RMP) of circular muscle (CM) cells. In the CM strip, methionine increased the amplitude and area under the curve (AUC) of contractions. In the whole segment of colon, methionine increased the amplitude and AUC of the high amplitude contractions in the CM. These effects on contraction were maximal at 10 microM and were not observed in longitudinal muscles in both the strip and the colon segment. Methionine reversed the effects of pretreatment with sodium nitroprusside, tetrodotoxin and Nw-oxide-L-arginine, resulting in depolarization of the RMP, and increased amplitude and AUC of contractions in the muscle strip. Methionine treatment affected the wave pattern of the colon segment by evoking small sized amplitude contractions superimposed on preexisting wave patterns. Our results indicate that a compound mimicking methionine may provide prokinetic functions in the human colon.
Area Under Curve ; Arginine/pharmacology ; Colon/drug effects/physiology ; Humans ; Membrane Potentials/drug effects ; Methionine/*pharmacology ; Microelectrodes ; Muscle Contraction/*drug effects ; Muscle, Smooth/drug effects/*physiology ; Nitroprusside/pharmacology ; Tetrodotoxin/pharmacology

BACKGROUND/AIMS: Tamoxifen is a widely used anticancer drug for breast cancer with frequent gastrointestinal side effects. Changes in gastrointestinal motility is associated with altered activities of membrane ion channels. Ion channels have important role in regulating membrane potential and cell excitability. This study was performed to investigate the effects of tamoxifen on the membrane ionic currents in colonic smooth muscle cells. METHODS: Murine colonic smooth muscle cells were isolated from the proximal colon using collagenase, and the membrane currents were recorded using a whole-cell patch clamp technique. RESULTS: Two types of voltage-dependent K+ currents were recorded (A-type and delayed rectifier K+ currents). Tamoxifen inhibited both types of voltage-dependent K+ currents in a dose-dependent manner. However, tamoxifen did not change the half-inactivation potential and the recovery time of voltage-dependent K+ currents. Chelerythrine, a protein kinase C inhibitor or phorbol 12, 13-dibutyrate, a protein kinase C activator did not affect the voltage-dependent K+ currents. Guanosine 5'-O-(2-thio-diphosphate) did not affect the tamoxifen-induced inhibition of voltage-dependent K+ currents. Tamoxifen inhibited voltage-dependent Ca2+ currents completely in whole-test ranges. CONCLUSIONS: These results suggest that tamoxifen can alter various membrane ionic currents in smooth muscle cells and cause some adverse effects on the gastrointestinal motility.
Animals ; Antineoplastic Agents, Hormonal/*pharmacology ; Calcium Channels/drug effects ; Colon/*drug effects/physiology ; English Abstract ; In Vitro ; Membrane Potentials ; Mice ; Myocytes, Smooth Muscle/*drug effects/physiology ; Potassium Channels/*drug effects ; Tamoxifen/*pharmacology

BACKGROUND/AIMS: Urocortin 1, a corticotropin-releasing factor related peptide, increases colonic motility under stressful conditions. We investigated the effect of urocortin 1 on colonic motility using an experimental model with isolated rat colon in which the blood flow and intestinal nerves were preserved. Furthermore, we assessed whether this effect was mediated by adrenergic or cholinergic nerves. METHODS: Colonic motility was measured in the proximal and distal parts of resected rat colon. The colon resected from the peritoneum was stabilized, and then urocortin 1 (13.8, 138, 277, and 1,388 pM) was administered via a blood vessel. Motility index was measured in the last 5 min of the 15 min administration of urocortin 1 and expressed as percentage change from baseline. Subsequently, the change in motility was measured by perfusing urocortin 1 in colons pretreated with phentolamine, propranolol, hexamethonium, atropine, or tetrodotoxin. RESULTS: At concentrations of 13.8, 138, 277, and 1,388 pM, urocortin 1 increased the motility of proximal colon (20.4+/-7.2%, 48.4+/-20.9%, 67.0+/-25.8%, and 64.2+/-20.9%, respectively) and the motility of distal colon (3.3+/-3.3%, 7.8+/-7.8%, 71.1+/-28.6%, and 87.4+/-32.5%, respectively). The motility induced by urocortin 1 was significantly decreased by atropine to 2.4+/-2.4% in proximal colon and 3.4+/-3.4% in distal colon (p<0.05). However, tetrodotoxin, propranolol, phentolamine, and hexamethonium did not inhibit motility. CONCLUSIONS: Urocortin 1 increased colonic motility and it is considered that this effect was directly mediated by local muscarinic cholinergic receptors.
Animals ; Colon/*drug effects/physiology ; Injections, Intravenous ; Male ; Muscle Contraction/drug effects ; Neurotransmitter Agents/pharmacology ; Rats ; Rats, Sprague-Dawley ; Receptors, Cholinergic/chemistry/metabolism ; Urocortins/isolation & purification/*pharmacology

OBJECTIVETo study the kinetogenic effects of serum containing Semen Arecae, Dandelion, Semen raphani and Atractylodes macrocephala on the colonic smooth muscle cells of rats.

METHODSSerum containing Chinese materia medicas was made according to standard methods. Smooth muscle cells were isolated from the muscle layers of Wistar rat's colon, referred to modified Bitar's method. The contractile response of colonic smooth muscle cells to serum containing Chinese materia medicas (10%, 50%, 100% concentration) and other medicines (blank and 1 x 10(-3) mol/L acetylcholine) were separately observed. The contractility was presented by the decrease of the cell length between the drug groups and the control.

RESULTSSerum containing each Chinese materia medica can make dose-dependent contraction at different concentrations (P < 0.05), but the strongest effect of each serum had no significant difference (P > 0.05).

CONCLUSIONSerum containing Semen Arecae, Dandelion, Semen raphani and Atractylodes macrocephala can make notable contraction on colonic smooth muscle cells in rats.

Animals ; Cells, Cultured ; Colon ; cytology ; Drugs, Chinese Herbal ; pharmacology ; Medicine, Chinese Traditional ; Muscle Contraction ; drug effects ; Muscle, Smooth ; cytology ; Myocytes, Smooth Muscle ; drug effects ; Rats

OBJECTIVETo study the pathogenic and tumorigenic effect of 1,2-dimethylhydrazine (DMH) on the colon and ovaries of mice.

METHODSSixty ICR female mice were randomly divided into groups A and B for intraperitoneal injection of DMH (20 mg/kg) and saline (control) once a week for 24 weeks, respectively. The mice were sacrificed at 12, 16, 20, 24, 28 and 32 weeks after the first DMH injection for pathological examination of the colon and ovaries.

RESULTSIn group A, colorectal adenomas were found in 7, colorectal adenocarcinomas in 5, and hemorrhagic lesions of the ovaries with chronic inflammatory in 21 mice. Choriocarcinoma in the ovaries were detected in one mouse at 28 weeks and in another at 32 weeks. No obvious pathological changes were found in group B following the injections.

CONCLUSIONIntraperitoneal injection of DMH may induce colon tumors and ovarian diseases in mice.

1,2-Dimethylhydrazine ; toxicity ; Animals ; Colon ; drug effects ; pathology ; Colonic Neoplasms ; chemically induced ; Female ; Mice ; Mice, Inbred ICR ; Ovarian Diseases ; chemically induced ; Ovary ; drug effects ; pathology

The aim of the present study was to investigate the effects of quercetin on colon contractility and voltage-dependent Ca(2+) channels in the single smooth muscle cell isolated from the proximal colon of guinea-pig and to clarify whether its effect on L-type Ca(2+) current (I(Ca,L)) would be related to its myorelaxing properties. Colon smooth muscle strips were used to take contractile tension recordings. Smooth muscle cells were freshly isolated from the proximal colon of guinea-pig by means of papain treatment. I(Ba,L) (barium instead of calcium as current carrier) was measured by using whole-cell patch-clamp techniques. The results showed that quercetin relaxed colon muscle strips in a concentration-dependent manner and antagonized the contractile effect of acetylcholine and neostigmine. Preincubation with indomethcin [cyclooxygenase (COX) inhibitor] and methylene blue [guanylate cyclase (GC) inhibitor] significantly attenuated the relaxing effect of quercetin, respectively. Quercetin increased I(Ba,L) in a concentration- [EC(50)= (7.59+/-0.38) mumol/L] and voltage-dependent pattern, and shifted the maximum of the current-voltage curve by 10 mV in the depolarizing direction without modifying the threshold potential for Ca(2+) influx. Quercetin shifted the steady-state inactivation curve toward more positive potentials by approximately 3.75 mV without affecting the slope of activation and inactivation curve. H-89 (PKA inhibitor) abolished quercetin-induced I(Ba,L) increase, while cAMP enhanced the quercetin-induced I(Ba,L) increase. The patch-clamp results proved that quercetin increased I(Ba,L) via PKA pathway. It is therefore suggested that the relaxing effect of quercetin attributes to the interaction of GC and COX stimulation, as well as the antagonism effect on acetylcholine, which hierarchically prevails over the increase in the Ca(2+) influx to be expected from I(Ca,L) stimulation.
Animals ; Calcium Channels, L-Type ; metabolism ; Cells, Cultured ; Colon ; drug effects ; Guinea Pigs ; Muscle Contraction ; Myocytes, Smooth Muscle ; drug effects ; Patch-Clamp Techniques ; Quercetin ; pharmacology