High-Energy Pacing in the Jejunum Elicits Pulsatile Segmental Contractions

OBJECTIVE

Compromised bowel function is associated with a range of motility disorders such as post-operative ileus and chronic intestinal pseudo-obstruction. Disordered or weak motility compromise the efficient movement of luminal contents necessary for digestion and nutrient absorption. This study investigated the potential of high-energy pacing to enhance contractions in the proximal jejunum of the small intestine.

METHODS

Pacing pulse parameters (pulse-width: 100 ms, 200 ms, 400 ms, pulse-amplitude: 4 mA, 6 mA, 8 mA) were systematically varied in the in vivo porcine jejunum (n = 7) and the induced contractile responses were evaluated using a video mapping system. Localized segmental contractions were quantified by measuring the intestinal diameter and thereby computing the strain. The impact of pacing parameters on contractile strain was investigated. Finally, histological studies were conducted on paced tissue to assess for potential tissue damage.

RESULTS

Segmental contractions were successfully induced at all pulse-settings and evaluated across 67 pacing sessions. In response to pacing, the intestine segment at the site of pacing contracted, with diameter reduced by 6-18%. Contractile response significantly increased with increasing pulse-amplitude. However, with increasing pulse-width, the increase in contractile response was significant only between 100 ms and 400 ms. Histology showed no tissue damage occurred when maximal pacing energy (pulse-amplitude = 4-8 mA, pulse-width = 400 ms, 5 minute duration) was applied.

CONCLUSION

High-energy pacing induced periodic segmental contractions in response to pacing pulses and the contractile strain was proportional to the energy applied on the intestine. The ability to enhance motility through pacing may hold promising therapeutic potential for bowel disorders and awaits clinical translation.

SIGNIFICANCE

Small intestine pacing elicits localized segmental contractions which increase in magnitude with increasing pulse settings. This study marks the first adaptation of video mapping techniques to track the pacing response in the small intestine.

Association between jejunal remodeling in fasting rats and hypersensitivity of intestinal afferent nerves to mechanical stimulation

Remodeling of Intestinal properties and hypersensitivity of intestinal afferents to mechanical stimulation were previously demonstrated in a fasting rat model. Other studies investigated the association between mechanical and histological remodeling during fasting. This study aimed to further explore the relationship between the jejunal remodeling and intestinal afferent hypersensitivity by combining afferent nerve recordings with histological and mechanical data. Eight male Sprague Dawley rats had no access to food for 7 days (Fasting group). Seven male rats served as controls (Control group). Jejunal segments were studied in vitro in an organ bath for analysis of afferent signaling and for analysis of mechanical and histomorphological parameters. Correlation analyses were done to analyze association between nerve activity (spike rate increase ratio, SRIR) at distension levels of 20, 40 and 80 cmH2O and mechanical stress and histomorphological changes of the jejunal segments. Compared with the Control group, the main findings in jejunal segments in the Fasting group were (1) Most histomorphometry parameters were reduced (P < 0.05-P < 0.001), (2) SRIR values were higher (P < 0.001), (3) The relative numbers of intermuscular and submucosal neurons were increased (P < 0.05-P < 0.01), and (4) SRIR was negatively correlated with intestinal wall thickness, circumferential muscle layer thickness and positively correlated with the inner residual strain, the number of neurons, and the mechanical stress. In conclusion, the fasting-induced histomorphological remodeling (reduced wall thickness and increased relative number of neurons) and biomechanical remodeling (residual strain changes and high stress level) of the intestine in fasting rats were associated with hypersensitivity of intestinal afferents. Afferent hypersensitivity appears to be dependent on stress rather than on strain.

Practical Considerations and Recommendations for “A Revised Hippocratic Oath for the Era of Digital Health” (Preprint)

The Hippocratic Oath (the “Oath”) is a longstanding body of ethical tenets that have undergone several amendments to accommodate changes and evolutions in the practice of medicine. In their recent perspective entitled, “A Revised Hippocratic Oath for the Era of Digital Health,” Meskó and Spiegel offered proposed amendments to the Oath to address both challenges and needs that follow digital health implementation in clinical practice. In this commentary, we offer additional thoughts and considerations to Meskó and Spiegel’s proposed amendments to accomplish two goals: (1) reflect on the shared goals and values of all digital health stakeholders and (2) drive home the focus on affirming patient choice, autonomy, and respect.

Allicin Improves Intestinal Epithelial Barrier Function and Prevents LPS-Induced Barrier Damages of Intestinal Epithelial Cell Monolayers

Gut barrier disruption is the initial pathogenesis of various diseases. We previously reported that dietary allicin improves tight junction proteins in the endoplasmic reticulum stressed jejunum. However, whether the allicin benefits the gut barrier within mycotoxin or endotoxin exposure is unknown. In the present study, IPEC-J2 cell monolayers within or without deoxynivalenol (DON) or lipopolysaccharide (LPS) challenges were employed to investigate the effects of allicin on intestinal barrier function and explore the potential mechanisms. Results clarified that allicin at 2 μg/mL increased the viability, whereas the allicin higher than 10 μg/mL lowered the viability of IPEC-J2 cells via inhibiting cell proliferation. Besides, allicin increased trans-epithelial electric resistance (TEER), decreased paracellular permeability, and enhanced ZO-1 integrity of the IPEC-J2 cell monolayers. Finally, allicin supplementation prevented the LPS-induced barrier damages via activating Nrf2/HO-1 pathway-dependent antioxidant system. In conclusion, the present study strongly confirmed allicin as an effective nutrient to improve intestinal barrier function and prevent bacterial endotoxin-induced barrier damages.

High-Resolution Spatiotemporal Quantification of Intestinal Motility with Free-Form Deformation

OBJECTIVE

To develop a method to quantify strain fields from in vivo intestinal motility recordings that mitigate accumulation of tracking error.

METHODS

The deforming geometry of the intestine in video sequences was modeled by a biquadratic B-spline mesh. Green-Lagrange strain fields were computed to quantify the surface deformations from motility. A nonlinear optimization scheme was applied to mitigate the accumulation of tracking error associated with image registration.

RESULTS

The optimization scheme maintained the RMS strain error under 1% and reduced the rate of strain error by 97% during synthetic tests. The algorithm was applied to map 64 segmental, 12 longitudinal, and 23 propagating circular contractions in the jejunum. Coordinated activity of the two muscle layers could be identified and the strain fields were able to map and quantify the anisotropic contractions of the intestine. Frequency and velocity were also quantified, from which two types of propagating circular contractions were identified: (i) -0:360:04 strain contractions that originated spontaneously and propagated at 31 mm/s in two pigs, and (ii) cyclic propagating contractions of -0:170:02 strain occurred at 11:00:6 cpm and propagated at 164 mm/s in a rabbit.

CONCLUSION

The algorithm simultaneously mapped the circular, longitudinal activity of the intestine with high spatial resolution and quantified anisotropic contractions and relaxations.

SIGNIFICANCE

The proposed algorithm can now be used to define the interactions of muscle layers during motility patterns. It can be integrated with high-resolution bioelectrical recordings to investigate the regulatory mechanisms of motility.

Water intake releases serotonin from enterochromaffin cells in rat jejunal villi

The present study aims to investigate the roles of water intake in serotonin production and release in rat jejunum. We evaluated the changes in concentrations of serotonin in the portal vein and mesenteric lymph vessel induced by the intragastric administration of distilled water. The density of granules in enterochromaffin cells and the immunoreactivity of serotonin in the jejunal villi were investigated before and after water intake. The effects of intravenous administration of serotonin and/or ketanserin on mesenteric lymph flow and concentrations of albumin and IL-22 in the lymph were also addressed. Water intake increased serotonin concentration in the portal vein, but not in the mesenteric lymph vessel. The flux of serotonin through the portal vein was significantly larger than that through the mesenteric lymph vessel. Water intake decreased the density of granules in the enterochromaffin cells and increased the immunoreactivity of serotonin in the jejunal villi. The intravenous administration of serotonin increased significantly mesenteric lymph flow and the concentrations of albumin and IL-22; both were significantly reduced by the intravenous pretreatment with ketanserin. We showed that serotonin released from enterochromaffin cells by water intake was mainly transported through the portal vein. Additionally, serotonin in blood was found to increase mesenteric lymph formation with permeant albumin in the jejunal villi via the activation of 5-HT2 receptor.

Jejunum: The understudied meeting place of dietary lipids and the microbiota

Although the jejunum is the main intestinal compartment responsible for lipid digestion and absorption, most of the studies assessing the impact of dietary lipids on the intestinal microbiota have been performed in the ileum, colon and faeces. This lack of interest in the jejunum is due to the much lower number of microbes present in this intestinal region and to the difficulty in accessing its lumen, which requires invasive methods. Recently, several recent publications highlighted that the whole jejunal microbiota or specific bacterial members are able to modulate lipid absorption and metabolism in enterocytes. This information reveals new strategies in the development of bacterial- and metabolite-based therapeutic interventions or nutraceutical recommendations to treat or prevent metabolic-related disorders, including obesity, cardiovascular diseases and malnutrition. This review is strictly focused on the following triad: dietary lipids, the jejunal epithelium and the jejunal microbiota. First, we will describe each member of the triad: the structure and functions of the jejunum, the composition of the jejunal microbiota, and dietary lipid handling by enterocytes and by microorganisms. Then, we will present the mechanisms leading to lipid malabsorption in small intestinal bacterial overgrowth (SIBO), a disease in which the jejunal microbiota is altered and which highlights the strong interactions among this triad. We will finally review the recent literature about the interactions among members of the triad, which should encourage research teams to further explore the mechanisms by which specific microbial strains or metabolites, alone or in concert, can mediate, control or modulate lipid absorption in the jejunum.

The effect of green kiwifruit on gas transit and tolerance in healthy humans

BACKGROUND

Green kiwifruit is a fiber-rich fruit that has been shown effective for treatment of constipation. However, fermentation of fibers by colonic bacteria may worsen commonly associated gas-related abdominal symptoms.

AIM

To determine the effect of green kiwifruit on transit and tolerance to intestinal gas in humans.

METHODS

In 11 healthy individuals, two gas challenge tests were performed (a) after 2 weeks on a low-flatulogenic diet and daily intake of 2 green kiwifruits and (b) after 2 weeks on a similar diet without intake of kiwifruits. The gas challenge test consisted in continuous infusion of a mixture of gases into the jejunum at 12 mL/min for 2 hours while measuring rectal gas evacuation, abdominal symptoms, and abdominal distension. During the 2 weeks prior to each gas challenge test (on-kiwifruit and off-kiwifruit), the number and consistency of stools, and abdominal symptoms were registered.

KEY RESULTS

Intake of kiwifruits was associated with more bowel movements per day (1.8 ± 0.1 vs 1.5 ± 0.1 off-kiwifruit; P = .001) and somewhat looser stools (Bristol score 3.3 ± 0.2 vs 2.8 ± 0.1 off-kiwifruit; P = .072) without relevant abdominal symptoms. Gas infusion produced similar gas evacuation (1238 ± 254 mL and 1172 ± 290 mL; P = .4355), perception of symptoms (score 1.2 ± 0.2 and 1.3 ± 0.3; P = .2367), and abdominal distension (17 ± 7 mm and 17 ± 6 mm; P = .4704) while on-kiwifruit or off-kiwifruit.

CONCLUSIONS AND INFERENCES

In healthy subjects, green kiwifruit increases stool frequency without relevant effects on intestinal gas transit and tolerance. If confirmed in patients, these fruits may provide a natural and well-tolerated treatment alternative for constipation.

Effects of thermal manipulation of eggs on the response of jejunal mucosae to posthatch chronic heat stress in broiler chickens

In this study, the aim was to investigate effects of chronic heat stress (CHS) on the mRNA levels of proinflammatory cytokines (interleukin [IL]-6, IL-8, IL-1β, and tumor necrosis factor alpha [TNF-α]), toll-like receptors (TLR2 and TLR4), heat shock proteins (Hsp70, heat shock transcription factor [HSF]-1, and HSF3) and antioxidant enzymes (catalase, glutathione peroxidase, NADPH oxidase, and superoxide-dismutase) in the jejunal mucosae of broiler chickens subjected to thermal manipulation (TM) during embryogenesis. TM was carried out at 39°C and 65% relative humidity (RH) for 18 h daily from embryonic days 10 to 18. Control group was incubated at 37.8°C and 56% RH. CHS was induced by raising the temperature to 35°C for 7 D throughout posthatch days 28 to 35. On post-hatch-day 28 (day zero of CHS) and after 1, 3, 5, and 7 D of CHS, the jejunal mucosae were collected from both groups to evaluate the mRNA levels by real-time reverse transcription-PCR analysis. On day zero of CHS, the mRNA levels of antioxidant enzymes, TLRs, HSF3, IL-1β, and TNF-α were not significantly different between TM and control groups, while the levels of IL-6, IL-8, and HSF1 were lower and the level of Hsp70 was higher in TM. However, during CHS, the mRNA levels of antioxidant enzymes, IL-1β, TNF-α, TLR4, and HSF1 were significantly lower in TM than in controls, while the levels of TLR2 and IL-8 were significantly higher in TM than in controls. In addition, TM led to significant increase of mRNA levels of IL-6 and HSF3 after 1 D and Hsp70 after 3 D of CHS and to significant decrease of mRNA levels of IL-6 after 3 and 5 D, HSF3 after 7 D, and Hsp70 after 5 D of CHS. Results of this study suggest that TM led to altered posthatch antioxidant, immunological, and Hsp response to CHS in the jejunal mucosae of broiler chickens, probably indicating that TM may mitigate the adverse effects of CHS.

Gastrointestinal and uterine smooth muscles relaxant and anti-inflammatory effects of corchorus olitorius leaf extract in laboratory animal models

ETHNO-PHARMACOLOGICAL RELEVANCE

Corchorus olitorius is reportedly used in ethno-medicine to arrest threatened miscarriage and other conditions associated with excessive uterine contractions. The plant is also used as a purgative, demulscent and an anti-inflammatory agent.

AIM OF THE STUDY

Against the background of ethno-medicinal use, this current work was designed to evaluate the gastrointestinal and uterine smooth muscles relaxant and anti-inflammatory effects of Corchorus olitorius leaf extract (COLE).

MATERIALS AND METHODS

Pieces of uterine and gastrointestinal tissues were suspended separately in organ baths containing ideal physiological salt solutions bubbled with air and were tested for responses to standard drugs and COLE, then repeated in the presence of antagonists. Anti-inflammatory study was carried out via the egg albumin-induced paw edema model in rats.

RESULTS

The application of COLE to pieces of uterine tissue significantly decreased the amplitudes of contractions in a dose dependent manner such that the highest dose applied (666.67 μg/ml) achieved a 100% inhibitory effect. Oxytocin induced contractions were also significantly inhibited by both salbutamol and COLE. On the isolated rabbit jejunum, the effect of COLE was also inhibitory and like atropine, significantly inhibited acetylcholine induced contractions. In the in vivo study, the extract inhibited charcoal meal movement in test rats when compared with control. Anti-inflammatory effect of COLE was significant and compared favourably with that of aspirin following in vivo trials.

CONCLUSIONS

COLE therefore, may be a good tocolytic, anti-diarrheal and anti-inflammatory agent and offers hope of new drug discovery for such uses.

A flavonoid driven phyto-pharmacological effects of Capparis decidua Edgew. in rodents

This study elicits the underlying mechanism(s) of Capparis decidua when used for different gut disorders. HPLC chromatogram of C. decidua extract (CD.Cr) and its respective fractions showed a variety of phytochemicals of which, kaempferol being in a high proportion. In mice, CD.Cr at doses of 70 and 150 mg/kg enhanced the wet feces output to 33 and 44% respectively as compared to carbachol (47.6%), while doses of 500 and 700 mg/kg, presented 41 and 70% safety against castor oil-driven diarrhea, respectively. Its flavonoid constituent, kaempferol at doses of (50 and 100 mg/kg) produced 51.7 and 82% safety when compared to nifedipine which provided 95% safety at dose of 40 mg/kg against castor oil-driven diarrhea like loperamide. In isolated jejunum preparations, C. decidua extract and its respective fractions (except pet-ether) produced atropine-sensitive inhibitory effects, whereas kaempferol and nifedipine showed atropine insensitive effects. Against high K⁺-induced contractions, C. decidua's fractions and kaempferol both exhibited a concentration-related non-specific inhibition while displacing the Ca⁺⁺ -CRCs to right-ward with suppression in maximal response like nifedipine. In isolated rat ileal preparations, CD.Cr and respective fractions elicited atropine-sensitive gut excitatory responses. In summary, this article reports C. decidua's laxative effect through cholinergic receptor activation as well as its antidiarrheal effects, where its flavonoid constituent kaempferol produces Ca⁺⁺ antagonist like activity, thus justifying C. decidua folk use in constipation and diarrhea.

Endoplasmic Reticulum Stress and Unfolded Protein Response Pathways Involved in the Health-Promoting Effects of Allicin on the Jejunum

Intestinal endoplasmic reticulum stress (ERS) triggered by adverse factors disturbs the normal function of the intestine. Allicin has been reported to promote intestinal health and development. In the present study, we established in vivo (35-day-old weaned piglets, 4-week-old mice) and in vitro (IPEC-J2 cell line) ERS models to explore the possible mechanisms by which allicin may benefit intestinal health. This study revealed the following: (1) allicin supplementation improved intestinal morphological indices and ameliorated mild ERS in the jejunum of the weaned piglets; (2) allicin supplementation decreased cellular reactive oxygen species and upregulated the XBP-1s signaling pathways in IPEC-J2 cells; (3) allicin supplementation reduced the prolonged ERS-mediated apoptosis of IPEC-J2 cells and in the jejunal tissues of the KM mice; (4) allicin supplementation enhanced the intercellular junction protein levels of jejunal cells by alleviating the prolonged ERS. These novel findings suggest that eating garlic could alleviate some intestinal malfunctions associated with ERS.

Effects of phospholipid and polyethylene glycol monostearate (100) on the in vitro and in vivo physico-chemical characterization of poly(n-butyl cyanoacrylate) nanoparticles

In this study, poly(n-butyl cyanoacrylate) nanoparticles (PBCA-NPs) modified with various amounts of soybean phospholipid (PC) and polyethylene glycol monostearate (S100) were prepared in order to investigate the effects of PC and S100 on the nanoparticles' physico-chemical properties, cytological properties and in vivo gastrointestinal absorption. Coumarin-6 (C6) was used as a fluorescent probe; C6-loaded PBCA-NPs modified with both PC and S100 (C6-PS-PBCA-NPs) were prepared using miniemulsion polymerization, and C6-loaded PBCA-NPs modified with either S100 (C6-S-PBCA-NPs) or PC (C6-P-PBCA-NPs) were used as references. All of the different NPs were shown to be stably dispersed and to have a small particle size. A cytotoxicity study indicated that all of the blank PBCA-NPs were safe and nontoxic. The uptake of NPs by Caco-2 cells was shown to be increased when the amount of PC was increased from 0% to 1.25% and the amount of S100 was increased from 0% to 0.725%. The use of a ligated intestinal loop model demonstrated that C6-PS-PBCA-NPs could rapidly penetrate a highly viscoelastic mucous layer, leading to an improvement in the absorption efficiency. During a pharmacokinetic study, C6-PS-PBCA-NPs improved the absorption of C6, as indicated by their higher Cmax and AUC0-t values compared with those of C6-S-PBCA-NPs or C6-P-PBCA-NPs. Overall, the results of this study indicate that PBCA-NPs modified with PC and S100 can enhance the absorption of orally administered drugs.

Epithelial restitution defect in neonatal jejunum is rescued by juvenile mucosal homogenate in a pig model of intestinal ischemic injury and repair

Intestinal ischemic injury results sloughing of the mucosal epithelium leading to host sepsis and death unless the mucosal barrier is rapidly restored. Volvulus and neonatal necrotizing enterocolitis (NEC) in infants have been associated with intestinal ischemia, sepsis and high mortality rates. We have characterized intestinal ischemia/repair using a highly translatable porcine model in which juvenile (6-8-week-old) pigs completely and efficiently restore barrier function by way of rapid epithelial restitution and tight junction re-assembly. In contrast, separate studies showed that younger neonatal (2-week-old) pigs exhibited less robust recovery of barrier function, which may model an important cause of high mortality rates in human infants with ischemic intestinal disease. Therefore, we aimed to further refine our repair model and characterize defects in neonatal barrier repair. Here we examine the defect in neonatal mucosal repair that we hypothesize is associated with hypomaturity of the epithelial and subepithelial compartments. Following jejunal ischemia in neonatal and juvenile pigs, injured mucosa was stripped from seromuscular layers and recovered ex vivo while monitoring transepithelial electrical resistance (TEER) and ³H-mannitol flux as measures of barrier function. While ischemia-injured juvenile mucosa restored TEER above control levels, reduced flux over the recovery period and showed 93±4.7% wound closure, neonates exhibited no change in TEER, increased flux, and a 11±23.3% increase in epithelial wound size. Scanning electron microscopy revealed enterocytes at the wound margins of neonates failed to assume the restituting phenotype seen in restituting enterocytes of juveniles. To attempt rescue of injured neonatal mucosa, neonatal experiments were repeated with the addition of exogenous prostaglandins during ex vivo recovery, ex vivo recovery with full thickness intestine, in vivo recovery and direct application of injured mucosal homogenate from neonates or juveniles. Neither exogenous prostaglandins, intact seromuscular intestinal layers, nor in vivo recovery enhanced TEER or restitution in ischemia-injured neonatal mucosa. However, ex vivo exogenous application of injured juvenile mucosal homogenate produced a significant increase in TEER and enhanced histological restitution to 80±4.4% epithelial coverage in injured neonatal mucosa. Thus, neonatal mucosal repair can be rescued through direct contact with the cellular and non-cellular milieu of ischemia-injured mucosa from juvenile pigs. These findings support the hypothesis that a defect in mucosal repair in neonates is due to immature repair mechanisms within the mucosal compartment. Future studies to identify and rescue specific defects in neonatal intestinal repair mechanisms will drive development of novel clinical interventions to reduce mortality in infants affected by intestinal ischemic injury.

A population of gut epithelial enterochromaffin cells is mechanosensitive and requires Piezo2 to convert force into serotonin release

Enterochromaffin (EC) cells constitute the largest population of intestinal epithelial enteroendocrine (EE) cells. EC cells are proposed to be specialized mechanosensory cells that release serotonin in response to epithelial forces, and thereby regulate intestinal fluid secretion. However, it is unknown whether EE and EC cells are directly mechanosensitive, and if so, what the molecular mechanism of their mechanosensitivity is. Consequently, the role of EE and EC cells in gastrointestinal mechanobiology is unclear. Piezo2 mechanosensitive ion channels are important for some specialized epithelial mechanosensors, and they are expressed in mouse and human EC cells. Here, we use EC and EE cell lineage tracing in multiple mouse models to show that Piezo2 is expressed in a subset of murine EE and EC cells, and it is distributed near serotonin vesicles by superresolution microscopy. Mechanical stimulation of a subset of isolated EE cells leads to a rapid inward ionic current, which is diminished by Piezo2 knockdown and channel inhibitors. In these mechanosensitive EE cells force leads to Piezo2-dependent intracellular Ca2+ increase in isolated cells as well as in EE cells within intestinal organoids, and Piezo2-dependent mechanosensitive serotonin release in EC cells. Conditional knockout of intestinal epithelial Piezo2 results in a significant decrease in mechanically stimulated epithelial secretion. This study shows that a subset of primary EE and EC cells is mechanosensitive, uncovers Piezo2 as their primary mechanotransducer, defines the molecular mechanism of their mechanotransduction and mechanosensitive serotonin release, and establishes the role of epithelial Piezo2 mechanosensitive ion channels in regulation of intestinal physiology.

Beef steers with average dry matter intake and divergent average daily gain have altered gene expression in the jejunum

The objective of this study was to determine the association of differentially expressed genes (DEG) in the jejunum of steers with average DMI and high or low ADG. Feed intake and growth were measured in a cohort of 144 commercial Angus steers consuming a finishing diet containing (on a DM basis) 67.8% dry-rolled corn, 20% wet distillers grains with solubles, 8% alfalfa hay, and 4.2% vitamin/mineral supplement. From the cohort, a subset of steers with DMI within ±0.32 SD of the mean for DMI and the greatest (high) and least (low) ADG were chosen for slaughter and jejunum mucosa collection ( = 8 for each group). Dry matter intake (10.1 ± 0.05 kg/d) was not different ( = 0.41) but ADG was greater in the high-gain group (2.17 and 1.72 ± 0.02 kg/d for the high- and low-ADG groups, respectively; < 0.01). A total of 13,747 genes were found to be expressed in the jejunum, of which 64 genes were differentially expressed between the 2 groups (corrected < 0.05). Ten of the DEG were upregulated in the low-ADG group and 54 were upregulated in the high-ADG group. Gene ontology analysis determined that 24 biological process terms were overrepresented ( < 0.05), including digestion, drug and xenobiotic metabolism, and carbohydrate metabolism. Additionally, 89 molecular function terms were enriched ( < 0.05), including metallopeptidase activity, transporter activity, steroid hydrolase activity, glutathione transferase activity, and chemokine receptor binding. Metabolic pathways (28 pathways) impacted by the DEG ( < 0.05) included drug and xenobiotic metabolism by cytochrome P450, carbohydrate digestion and absorption, vitamin digestion and absorption, galactose metabolism, and linoleic acid metabolism. Results from this experiment indicate that cattle with average DMI and greater ADG likely have a greater capacity to handle foreign substances (xenobiotics). It is also possible that cattle with a greater ADG have a greater potential to digest and absorb nutrients in the small intestine.

In vivo performance of a visible wavelength optical sensor for monitoring intestinal perfusion and oxygenation

Traumatic injury resulting in hemorrhage is a prevalent cause of death worldwide. The current standard of care for trauma patients is to restore hemostasis by controlling bleeding and administering intravenous volume resuscitation. Adequate resuscitation to restore tissue blood flow and oxygenation is critical within the first hours following admission to assess severity and avoid complications. However, current clinical methods for guiding resuscitation are not sensitive or specific enough to adequately understand the patient condition. To better address the shortcomings of the current methods, an approach to monitor intestinal perfusion and oxygenation using a multiwavelength (470, 560, and 630 nm) optical sensor has been developed based on photoplethysmography and reflectance spectroscopy. Specifically, two sensors were developed using three wavelengths to measure relative changes in the small intestine. Using vessel occlusion, systemic changes in oxygenation input, and induction of hemorrhagic shock, the capabilities and sensitivity of the sensor were explored in vivo. Pulsatile and nonpulsatile components of the red, blue, and green wavelength signals were analyzed for all three protocols (occlusion, systemic oxygenation changes, and shock) and were shown to differentiate perfusion and oxygenation changes in the jejunum. The blue and green signals produced better correlation to perfusion changes during occlusion and shock, while the red and blue signals, using a new correlation algorithm, produced better data for assessing changes in oxygenation induced both systemically and locally during shock. The conventional modulation ratio method was found to be an ineffective measure of oxygenation in the intestine due to noise and an algorithm was developed based on the Pearson correlation coefficient. The method utilized the difference in phase between two different wavelength signals to assess oxygen content. A combination of measures from the three wavelengths provided verification of oxygenation and perfusion states, and showed promise for the development of a clinical monitor.

Dual mechanisms of anti-muscarinic and Ca++ antagonistic activities to validate the folkloric uses of Cyperus niveus Retz. as antispasmodic and antidiarrheal

ETHNOPHARMACOLOGICAL RELEVANCE

Cyperus species are famous for their traditional uses and very commonly used for their anti-spasmodic and anti-diarrheal activities. Cyperus niveus Retz. is used in local traditional system of medicine in Pakistan to treat diarrhea and emesis.

AIM OF THE STUDY

The aim of the study was to validate the traditional uses and to provide the possible mechanisms for the medicinal use of Cyperus niveus Retz. as anti-spasmodic, anti-diarrheal and anti emetic.

MATERIALS AND METHODS

The in-vivo studies of anti-diarrheal, charcoal meal GI transit test and anti-emetic activities were conducted in rats, mice and chicks respectively, while isolated tissues of rabbit's jejunum and rat's ileum were used for in-vitro experiments. Phytochemical analysis was also undertaken.

RESULTS

The phytochemical study of hydro-ethanolic extract of Cyperus niveus Retz. showed the presence of flavonoids, phenols, alkaloids, tannins, saponins and glycosides. Cn. Cr caused significant inhibition of castor oil-induced diarrhea in rats (300,500 & 700mg/kg) using loperamide (10mg/kg, p.o) as standard. Cn. Cr also significantly decreased the motility in charcoal meal GI transit test at 100-200mg/kg in mice, using atropine (3.0mg/kg) as positive control. In jejunum tissue, Cn. Cr relaxed carbachol(1µM) and K⁺(80mM)-induced contractions, similar to the effect of dicyclomine. Pre-incubation of isolated rat ileum tissues with Cn. Cr (0.1mg/mL) caused the corresponding shift of CCh concentration response curve (CRC) to right without decrease in max. response whereas at the concentration of 0.3mg/mL caused the rightward nonparallel shift with max. response suppression, similar to dicyclomine. Antimuscarinic effect was further confirmed when prior administration of Cn. Cr (0.1, 0.3 and 1mg/mL) caused concentration dependent inhibition of induced contractions of carbachol, comparable to atropine (1µM). To confirm the Ca²⁺ channel blocking (CCB), the rabbit jejunum was pre-incubated with Cn. Cr (0.3 & 1.0mg/mL), produced a shift in CRCs of calcium toward right with decrease in the maximum response at next concentration, similar to that of dicyclomine. The organic fraction of Cyperus niveus Retz. (Cn. Dcm) showed Ca²⁺ antagonist and anticholinergic activities with higher potency against K⁺(80mM) induced contractions, like verapamil, while aqueous fraction (Cn. Aq) relaxed only carbachol(1µM) induced contractions with no prominent effect on K⁺ (80mM)-contractions even at the higher concentration of 10mg/mL, similar to atropine. Cn. Cr also showed significant anti-emetic effect in Chick emesis model using chlorpromazine as standard.

CONCLUSION

This study shows the presence of antidiarrheal and spasmolytic activities in Cyperus niveus Retz. extract, mediated by dual blocking mechanisms of muscarinic receptors and Ca²⁺ channels. The results further indicate the presence of anti-emetic activity in Cn. Cr, which may be because of its anti-muscarinic potential. This study provides the scientific bases to the traditional use of Cn. Cr in diarrhea and emesis.

A mechanistic evaluation of the traditional uses of Nepeta ruderalis in gastrointestinal and airway disorders

CONTEXT

Nepeta ruderalis Buch.-Ham. (Lamiaceae), locally known as Badranj Boya, is an aromatic herb used traditionally as an antispasmodic, antidiarrhoeal, and anti-asthamatic remedy.

OBJECTIVE

Aqueous methanolic extract of N. ruderalis was studied to investigate its traditional uses.

MATERIALS AND METHODS

Study was conducted from September 2015 to February 2016. In vitro spasmolytic and broncho-relaxant activity of crude extract of N. ruderalis (whole plant) was evaluated at 0.01-10 mg/mL final bath concentration in isolated rabbit jejunum and tracheal tissues, using PowerLab data acquisition system (Transonic Systems Inc., Ithaca, NY). In vivo antidiarrhoeal activity was evaluated in castor oil-induced diarrhoeal mice at the dose of 300 and 500 mg of crude extract orally.

RESULTS

Crude extract of N. ruderalis completely relaxed spontaneously contracting, high K⁺ (80 mM) and carbachol (1 μM) induced contracted jejunum with an EC₅₀ value of 5.85 (5.45-6.27), 4.0 (3.80-4.23) and 2.86 (2.48-3.29), similar to verapamil. Nr.Cr relaxed high K⁺ and carbachol induced contractions, at 5 and 10 mg/mL with an EC₅₀ value of 2.37 (2.11-2.67) and 3.26 (2.9-3.67), respectively, and also displaced calcium concentration-response curves toward right at 0.1 and 0.3 mg/mL. Nr.Cr exhibited antidiarrhoeal protection at a dose of 300 and 500 mg/kg, similar to verapamil, whereas no acute toxicity signs were seen up to 5 g/kg in healthy mice.

DISCUSSION AND CONCLUSION

Results suggest the presence of spasmolytic and broncho-relaxant effects in the crude extract of N. ruderalis, possibly mediated through calcium channel-blocking activity, providing the pharmacological basis for its traditional uses in gastrointestinal and airway disorders.

Effect of feeding soybean meal and differently processed peas on intestinal morphology and functional glucose transport in the small intestine of broilers

Peas are locally grown legumes being rich in protein and starch. However, the broad usage of peas as a feed component in poultry nutrition is limited to anti-nutritional factors, which might impair gut morphology and function. This study investigated the effect of feeding raw or differently processed peas compared with feeding a soybean meal-based control diet (C) on intestinal morphology and nutrient transport in broilers. A total of 360 day-old broiler chicks were fed with one of the following diets: The C diet, and 3 diets containing raw peas (RP), fermented peas (FP) and enzymatically pre-digested peas (EP), each supplying 30% of dietary crude protein. After 35 d, jejunal samples of broilers were taken for analyzing histomorphological parameters, active glucose transport in Ussing chambers and the expression of genes related to glucose absorption, intestinal permeability and cell maturation. Villus length (P = 0.017) and crypt depth (P = 0.009) of EP-fed broilers were shorter compared to birds received C. The villus surface area was larger in broilers fed C compared to those fed with the pea-containing feed (P = 0.005). Glucose transport was higher for broilers fed C in comparison to birds fed with the EP diet (P = 0.044). The sodium-dependent glucose co-transporter 1 (SGLT-1) expression was down-regulated in RP (P = 0.028) and FP (P = 0.015) fed broilers. Correlation analyses show that jejunal villus length negatively correlates with the previously published number of jejunal intraepithelial T cells (P = 0.014) and that jejunal glucose transport was negatively correlated with the occurrence of jejunal intraepithelial leukocytes (P = 0.041). To conclude, the feeding of raw and processed pea containing diets compared to a soybean based diet reduced the jejunal mucosal surface area of broilers, which on average was accompanied by lower glucose transport capacities. These morphological and functional alterations were associated with observed mucosal immune reactions. Further studies are required elucidating the specific components in peas provoking such effects and whether these effects have a beneficial or detrimental impact on gut function and animal health.

Role of muscarinic receptors in the contraction of jejunal smooth muscle in the horse: An in vitro study

Nonselective antimuscarinic drugs are clinically useful in several pathologic conditions of horses, but, blocking all muscarinic receptor (MR) subtypes, may cause several side effects. The availability of selective antimuscarinic drugs could improve therapeutic efficacy and safety. We aimed to enlighten the role of different MR subtypes by evaluating the effects of nonselective, and selective M₁, M₂ and M₃ MR antagonists on the contractions of horse jejunum. Segments of circular muscle of equine jejunum, were put into organ baths, connected to isotonic transducers, and the effects on ACh concentration-response curves, and on electrical field stimulation (EFS)-evoked contractions of intestinal preparations, induced by nonselective or selective MR antagonists, compared to pre-drug level, were studied. Atropine (nonselective MR antagonist), pirenzepine (selective M₁ antagonist), and p-FHHSiD (selective M₃ antagonist) competitively antagonized ACh (pA₂=9.78±0.21; 7.14±0.25 and 7.56±0.17, respectively). Methoctramine (selective M₂ antagonist) antagonized ACh in a concentration-unrelated fashion; however, it competitively antagonized carbachol, a nonselective muscarinic agonist (pA₂=6.42±0.23). Atropine dose-dependently reduced EFS-evoked contractions, reaching a maximal effect of -45.64±6.54%; the simultaneous block of neurokinin receptors, almost completely abolished the atropine-insensitive contractions. p-FHHSiD dose-dependently reduced EFS-induced contractions, while pirenzepine caused a minor decrease. Methoctramine, ineffective up to 10^-7M, enhanced the contractions at 10^-6M; the block of neurokinin receptors abolished the increase of contraction. Cholinergic contractions of horse jejunum are mainly mediated by M₃ receptors; M₂ selective antagonists seem to scarcely affect cholinergic, and to enhance neurokininergic contractions of equine jejunum, thus their use entails a lower risk of causing intestinal hypomotility, compared to nonselective drugs.

The 5-HT4 receptor agonist prucalopride does not facilitate cholinergic neurotransmission in circular and longitudinal smooth muscle preparations of equine mid-jejunum

BACKGROUND

Postoperative ileus (POI) remains an important cause of death in horses. The recently developed selective 5-HT₄ receptor agonists such as prucalopride target 5-HT₄ receptors on myenteric cholinergic neurons to enhance acetylcholine release and GI motility. No clearcut in vitro evaluation whether highly selective 5-HT₄ receptor agonists enhance submaximal cholinergic neurotransmission towards the muscle layer has been performed in horses.

OBJECTIVES

To identify functional 5-HT₄ receptors in equine jejunum.

STUDY DESIGN

In vitro experimental study.

METHODS

Circular and longitudinal smooth muscle strips (mid-jejunum) were mounted in organ baths between 2 platinum electrodes allowing electrical field stimulation (EFS). To delineate the conditions to obtain purely cholinergic responses, voltage-response curves were studied. To investigate the influence of prucalopride and 5-HT, submaximal cholinergic contractions at a single voltage were induced.

RESULTS

In circular and longitudinal strips, EFS induced voltage-dependent neurogenic on-contractions when the bathing medium contained a NO-synthesis inhibitor and apamin to prevent inhibitory responses to NO and ATP. Contractions at a voltage inducing 50% of maximal amplitude were cholinergic, as they were blocked by atropine. These contractions were not influenced by prucalopride (up to 3μM), even in the presence of the phosphodiesterase inhibitor isobutyl-methyl-xanthine to inhibit breakdown of the second messenger of 5-HT₄ receptors, cAMP. Also the full 5-HT₄ receptor agonist 5-HT did not influence the EFS-induced submaximal cholinergic contractions. Moreover, prucalopride did not influence muscle tone continuously enhanced with KCl.

CONCLUSIONS

There are no functional 5-HT₄ receptors on myenteric cholinergic neurons nor muscular 5-HT₄ receptors in equine jejunum.

Finishing pigs that are divergent in feed efficiency show small differences in intestinal functionality and structure

Controversial information is available regarding the feed efficiency-related variation in intestinal size, structure and functionality in pigs. The present objective was therefore to investigate the differences in visceral organ size, intestinal morphology, mucosal enzyme activity, intestinal integrity and related gene expression in low and high RFI pigs which were reared at three different geographical locations (Austria, AT; Northern Ireland, NI; Republic of Ireland, ROI) using similar protocols. Pigs (n = 369) were ranked for their RFI between days 42 and 91 postweaning and low and high RFI pigs (n = 16 from AT, n = 24 from NI, and n = 60 from ROI) were selected. Pigs were sacrificed and sampled on ~day 110 of life. In general, RFI-related variation in intestinal size, structure and function was small. Some energy saving mechanisms and enhanced digestive and absorptive capacity were indicated in low versus high RFI pigs by shorter crypts, higher duodenal lactase and maltase activity and greater mucosal permeability (P < 0.05), but differences were mainly seen in pigs from AT and to a lesser degree in pigs from ROI. Additionally, low RFI pigs from AT had more goblet cells in duodenum but fewer in jejunum compared to high RFI pigs (P < 0.05). Together with the lower expression of TLR4 and TNFA in low versus high RFI pigs from AT and ROI (P < 0.05), these results might indicate differences in the innate immune response between low and high RFI pigs. Results demonstrated that the variation in the size of visceral organs and intestinal structure and functionality was greater between geographic location (local environmental factors) than between RFI ranks of pigs. In conclusion, present results support previous findings that the intestinal size, structure and functionality do not significantly contribute to variation in RFI of pigs.

The effect of glyphosate-based herbicide Roundup and its co-formulant, POEA, on the motoric activity of rat intestine - In vitro study

The study was aimed at evaluating the effect of Roundup, polyoxyethylene tallow amine (POEA) and mixture of glyphosate and POEA in different levels on the motoric activity of jejunum strips. The incubation in the Roundup solutions caused a significant, mostly miorelaxant, reversible reaction of smooth muscle; only in the highest tested dose which is equivalent to the agricultural concentration (1% corresponding to 1.7g glyphosate/L) there was an irreversible disturbance of the spontaneous contractility and reactivity. The incubation in POEA solutions in the range of low doses (0.256; 1.28; 6.4mg/L) resulted in a biphasic muscle reaction (relaxation and contraction); whereas in the range of high doses, i.e. 32; 160 and 800mg/L (agricultural spray concentrations) induced only a miorelaxant, irreversible response. The results indicate very high toxicity of POEA which exceeds the toxicity of the commercial formulations. Besides, it is postulated that glyphosate and POEA may display antagonistic interaction towards the motoric activity of gastrointestinal tract.

Bovine milk-based formula leads to early maturation-like morphological, immunological, and functional changes in the jejunum of neonatal piglets

Artificial rearing and formula feeding is coming more into the focus due to increasing litter sizes and limited nursing capacity of sows. The formula composition is important to effectively support the development of the gut and prevent intestinal dysfunction in neonatal piglets. In this study, newborn piglets ( = 8 per group) were fed a bovine milk-based formula (FO), containing skimmed milk and whey as the sole protein and carbohydrate sources, or were suckled by the sow (sow milk [SM]). After 2 wk, tissue from the jejunum was analyzed for structural (i.e., morphometry) and functional (i.e., disaccharidase activity, glucose transport, permeability toward macromolecules, and immune cell presence) changes and concomitant expression of related genes. Formula-fed piglets had more liquid feces ( < 0.05) over the entire experimental period. Although FO contained twice as much lactose (46% on a DM basis) as SM (21%) and no maltose or starch, the lactase activity was lower ( < 0.05) and glucose transport capacity was higher ( < 0.05) in FO-fed pigs. The relative proportion of intraepithelial natural killer cells and proinflammatory cytokine gene expression (, , and ) was higher in FO-fed pigs ( < 0.05). Piglets fed FO had deeper crypts, larger villus area, and higher expression of caspase 3 and proliferating cell nuclear antigen ( < 0.05). Epithelial permeability toward fluorescein isothiocyanate-dextran was higher and expression of claudin-4 was lower in FO-fed piglets ( < 0.05). The data suggest an early response to bovine milk-based compounds in the FO accompanied with early onset of functional maturation and impaired barrier function. Whether lactose, absence of species-specific protective factors, or antigenicity of foreign proteins lead to to the observed intestinal reactions requires further clarification.

Current statins show calcium channel blocking activity through voltage gated channels

BACKGROUND

Statins are used for treatment of hypercholestremia. Common adverse reports associated with use of statins are generalized bodyache, rhabdomyolysis, muscles weakness and gastrointestinal disorders. The current work is an attempt to explain how smooth muscles of gastrointestinal tissues are affected by the current statins (Simvastatin, atorvastatin, fluvastatin and rosuvastatin).

METHODS

Effects of the current statins were studied on spontaneous activity of isolated rabbits' jejunal preparations. Different molar concentrations (10(-12)-10(-2)M) of the statins were applied on spontaneously contracting rabbits' jejunal preparations. As statins relaxed spontaneous activity, so we tested the statins on KCl (80 mM) induced contractions in similar test concentrations. Positive relaxant statins were tested again through construction of Calcium Concentration Response Curves (CCRCs) in the absence and presence of the statins using verapamil, a standard calcium channel blocker. CCRCs of statins were compared with CCRCs of verapamil.

RESULTS

Simvastatin, atorvastatin, fluvastatin and rosuvastatin relaxed the spontaneous and KCl-induced contractions. IC50 for simvastatin on spontaneous rabbit's jejunal preparations is -5.08 ± 0.1 Log 10 M. Similarly, IC50 for KCl-induced contractions is -4.25 ± 0.01 Log 10 M. Mean IC50 (Log 10 M) for atorvastatin on spontaneous rabbit's jejunal preparations and KCl-induced contractions are -5.19 ± 0.07 and -4.37 ± 0.09, respectively. Fluvastatin relaxed spontaneous activity of rabbits' jejunal preparations with an IC50 (Log 10 M) -4.5 ± 0.03. Rosuvastatin relaxed spontaneous as well as KCl (80 mM) induced contractions with respective IC50 (Log 10 M) -3.62 ± 0.04 and -4.57 ± 0.06. In case of CCRCs, tissues pre-treated with 4.6 μg/ml of simvastatin, have IC50 = -1.84 ± 0.03 [log (Ca(++)) M] vs control IC50 = -2.54 ± 0.04 [log (Ca(++)) M]. Similarly, atorvastatin, fluvastatin and rosuvastatin produced significant right shift in IC50 for CCRCs (P ≤ 0.05). In case of verapamil, IC50 for control curves is -2.45 ± 0.06 [log (Ca (++)) M], while IC50 in presence of verapamil (0.1 μM) is -1.69 ± 0.05 [log (Ca (++)) M]. Statins produced right shift in the IC50 of CCRCs. The effects of statins are like that of effects of verapamil, a standard calcium channel blocker.

CONCLUSIONS

Our findings suggest that current statins have calcium antagonistic effects that act on voltage gated calcium channels that may provide a rationale for cause muscle weakness and gastrointestinal disorders.

Rationalizing ethnopharmacological uses of Alternanthera sessilis: A folk medicinal plant of Pakistan to manage diarrhea, asthma and hypertension

ETHNOPHARMACOLOGICAL RELEVANCE

Tribal herbal practitioners of Pakistan use Alternanthera sessilis (Amaranthaceae) to treat diarrhea, asthma and hypertension.

OBJECTIVE

The current study was conducted to provide mechanistic basis for anti-spasmodic, anti- asthmatic and anti-hypertensive use of Alternanthera sessilis.

MATERIALS AND METHODS

The crude ethanolic extract of Alternanthera sessilis (As.Cr) and its fractions were tested in- vitro on isolated rabbit tissue preparations (i.e., jejunum, trachea, and aorta) and in-vivo in ketamin-diazepam anaesthetized normotensive rats.The responses were recorded using isotonic and isometric transducers coupled with Power Lab data acquisition system.

RESULTS

On isolated rabbit jejunum preparations, As.Cr exerted concentration-dependent (0.01-1.0mg/ml) spasmolytic effect and caused relaxation of K(+)(80mM)-induced spastic contractions. Furthermore, there was non-parallel shift in Ca(++)concentration response curves (CRCs) towards right at tissue bath concentrations of 0.1 and 0.3mg/ml. On isolated rabbit trachea, it relaxed carbachol (1μM)- and K(+()80mM)-induced contractions at respective tissue bath concentrations of 5.0 and 1.0mg/ml. On isolated rabbit aorta, it also demonstrated relaxant effect on phenylephrine (1μM)- and K(+()80mM)-induced contractions at tissue bath concentrations of 5.0 and 3.0mg/ml respectively. These findings were found to be comparable with verapamil, a reference Ca(++)channel blocker (CCB). The solvent-solvents fractionation revealed domination of spasmolytic effects in dichloromethane fraction as compared to aqueous fraction. Intravenous administration of As.Cr decreased mean arterial blood pressure, systolic blood pressure and diastolic blood pressure of ketamine-diazepam anaesthetized normotensive albino rats dose-dependently, at dose range of 1-10mg/kg.

CONCLUSION

Our results reflected presence of Ca(++) channel blocking (CCB) activity in As.Cr, thus rationalizing medicinal use of Alternanthera sessilis in diarrhea, asthma and hypertension.

A Simple, Realistic Stochastic Model of Gastric Emptying

Several models of Gastric Emptying (GE) have been employed in the past to represent the rate of delivery of stomach contents to the duodenum and jejunum. These models have all used a deterministic form (algebraic equations or ordinary differential equations), considering GE as a continuous, smooth process in time. However, GE is known to occur as a sequence of spurts, irregular both in size and in timing. Hence, we formulate a simple stochastic process model, able to represent the irregular decrements of gastric contents after a meal. The model is calibrated on existing literature data and provides consistent predictions of the observed variability in the emptying trajectories. This approach may be useful in metabolic modeling, since it describes well and explains the apparently heterogeneous GE experimental results in situations where common gastric mechanics across subjects would be expected.

Depression, anxiety and non-motor symptoms on initiation of intrajejunal levodopa/carbidopa therapy

In Parkinson's disease (PD), clinical observations and some studies suggest that depression and anxiety are linked to motor fluctuations. We studied prospectively 10 patients with advanced PD just before initiation of intrajejunal levodopa/carbidopa therapy, and after 1 and 3 months of regular treatment. Motor symptoms, motor fluctuations, non-motor symptoms, quality of sleep, symptoms of depression and anxiety were evaluated with the appropriate scales. As expected, motor symptoms and motor fluctuations improved considerably. Non-motor symptoms, quality of sleep and depression also improved significantly. However, anxiety score remained unchanged during the study. Our data in a small numbers of patients indicate that all aspects of mental and psychic symptoms are not alleviated within a short period of reduction of motor fluctuations.

Oral administration of putrescine and proline during the suckling period improves epithelial restitution after early weaning in piglets

Polyamines are necessary for normal integrity and the restitution after injury of the gastrointestinal epithelium. The objective of this study was to investigate the effects of oral administration of putrescine and proline during the suckling period on epithelial restitution after early weaning in piglets. Eighteen neonatal piglets (Duroc × Landrace × Large Yorkshire) from 3 litters (6 piglets per litter) were assigned to 3 groups, representing oral administration with an equal volume of saline (control), putrescine (5 mg/kg BW), and proline (25 mg/kg BW) twice daily from d 1 to weaning at 14 d of age. Plasma and intestinal samples were obtained 3 d after weaning. The results showed that oral administration of putrescine or proline increased the final BW and ADG of piglets compared with the control (P < 0.05). Proline treatment decreased plasma D-lactate concentration but increased the villus height in the jejunum and ileum, as well as the percentage of proliferating cell nuclear antigen (PCNA) positive cells and alkaline phosphatase (AKP) activity in the jejunal mucosa (P < 0.05). The protein expressions for zonula occludens (ZO-1), occludin, and claudin-3 (P < 0.05) but not mRNA were increased in the jejunum of putrescine- and proline-treated piglets compared with those of control piglets. The voltage-gated K+ channel (Kv) 1.1 protein expression in the jejunum of piglets administrated with putrescine and the Kv1.5 mRNA and Kv1.1 protein levels in the ileum of piglets administrated with proline were greater than those in control piglets (P < 0.05). These findings indicate that polyamine or its precursor could improve mucosal proliferation, intestinal morphology, as well as tight junction and potassium channel protein expressions in early-weaned piglets, with implications for epithelial restitution and barrier function after stress injury.

Rebamipide Promotes the Regeneration of Aspirin-Induced Small-Intestine Mucosal Injury through Accumulation of β-Catenin

BACKGROUND

The effect of rebamipide on repairing intestinal mucosal damage induced by nonsteroidal anti-inflammatory drugs and its mechanism remain unclear. In this study, we sought to explore the mechanism whereby rebamipide could promote the regeneration of aspirin-induced intestinal mucosal damage.

METHODS

BALB/c mice were administered aspirin (200 mg/kg/d) for 5 days to induce acute small intestinal injury (SII). Subsequently, SII mice were treated with rebamipide (320 mg/kg/d) for 5 days. The structure of intestinal barrier was observed with transmission electron microscope, and Zo-1 and occludin expressions were detected. The proliferative index was indicated by the percentage of proliferating cell nuclear antigen positive cells. The prostaglandin E2 (PGE2) levels in the small intestine tissues were measured by an enzyme immunoassay. The mRNA and protein expression levels of cyclooxygenase (COX) and β-catenin signal were detected in the small intestine using quantitative PCR and Western blot, respectively.

RESULTS

COX expression was significantly down-regulated in aspirin induced SII (P < 0.05). In SII mice treated with rebamipide, histopathological findings of aspirin-induced intestinal inflammation were significantly milder and tight junctions between intestinal epithelial cells were improved significantly. The proliferative index increased after rebamipide treatment when compared with that in the control mice. The expressions of COX-2, β-catenin, and c-myc and the PGE2 concentrations in small intestinal tissues were significantly increased in mice with rebamipide treatments (P < 0.05).

CONCLUSION

Rebamipide administration in aspirin-induced SII mice could improve the intestinal barrier structure and promote the regeneration of small intestinal epithelial injury through up-regulating COX-2 expression and the accumulation of β-catenin.

Effect of manual acupuncture on bowel motility in normal kunming mouse

OBJECTIVE

To observe the effects of acupuncture on motility of jejunum and distal colon at different acupoints on normal Kunming mice.

METHODS

The jejunal and colorectal motor activity of forty Kunming mice were recorded by the intra-intestinal capsule. The capsules contained with distilled water were placed into the cavities of jejunum and distal colon. The changes of bowel were compared with the background activity recorded before any stimulation. The chosen acupoints were as follows: Zusanli (ST 36) on the lower legs, Tianshu (ST 25) on the mid-lower abdomen.

RESULTS

Manual acupuncture (MA) at Zusanli (ST 36) significantly promoted the motility of jejunum and distal colon (manifested as increased change rate of average amplitude and increased change rate of mean area under the contractile curve) of normal Kunming mice (P < 0.01). MA at Tianshu (ST 25) significantly inhibited the motility of jejunum (manifested as decreased change rate of average amplitude, decreased change rate of mean area under the contractile curve, and the reduced frequency) of normal Kunming mice (P < 0.01), while significantly increased the distal colonic motility (manifested as increased amplitude and increased mean area under the contractile curve) of normal Kunming mice (P < 0.01).

CONCLUSION

MA at specific acupoints [Zusanli (ST 36), Tianshu (ST 25)] has different effects on the motility of jejunum and distal colon, which might involve the segmental innervations of the related nerve.

In vitro relaxant and spasmolytic effects of essential oil of Pistacia integerrima Stewart ex Brandis Galls

ETHNOPHARMACOLOGICAL RELEVANCE

Pistacia integerrima J.L. Stewart ex Brandis (Family: Anacardiaceae) galls are used in Indian ethnomedicine for its anti-asthmatic, sedative and spasmolytic properties, however, there are no scientific studies demonstrating its spasmolytic activity. The present investigation deals with the evaluation of relaxant and spasmolytic activities of the essential oil isolated from the galls of Pistacia integerrima J.L. Stewart ex Brandis (EOPI).

MATERIALS AND METHODS

In vitro pharmacological assays were carried out on rabbit jejunum spontaneous contractions, guinea pig ileum. The present investigation studied the relaxation of basal tone of isolated guinea pig ileum by possible involvement of NO, prostaglandins, membrane Na(+) channels, potassium channel, enteric nervous system, adrenoceptors, Ca(2+) channels. Additional studies were conducted for comparison of the relaxant effects of EOPI on CaCl2 induced contraction in calcium free tyrode solution, effect on nifedipine insensitive component of ACh-induced contraction and on the contractile machinery to intracellular [Ca(2+)] on isolated guinea pig ileum.

RESULTS

EOPI at non-relaxing dose potentiated the isoprenaline induced relaxation of rabbit jejunum. EOPI (50 µg/mL) exhibited 28% relaxation of basal tone of 60 mM K(+) induced contraction which is unaltered by preincubation with 0.5 mM hexamethonium, 0.5 µM Tetrodotoxin, 1 µM indomethacin, and 100 µM L-NG-Nitroarginine Methyl Ester (L-NAME). EOPI inhibited Ca(2+) induced contraction of isolated guinea pig ileum in Ca(2+) free medium. EOPI (10 µg/ml) potentiated the reversal of a KCl-induced tonic contraction has been observed in Ca(2+) free medium.

CONCLUSION

The present investigation reinforces the use of Pistacia integerrima Stewart ex Brandis as antispasmodic in folk medicine. Moreover, it is demonstrated the involvement of β- adrenoceptors and calcium channels in this activity, but not the participation of nicotinic receptors, Na(+) channels, prostaglandins or nitric oxide.

Isolation and evaluation of the myorelaxant effect of bergapten on isolated rat jejunum

CONTEXT

Plants of the genus Heracleum L. (Apiaceae) have a long history of being used in traditional medicines for the treatment of alimentary tract disorders, and these biological effects have been ascribed to the presence of furanocoumarins (including bergapten).

OBJECTIVES

This study aimed to develop an efficient, preparative, counter-current chromatographic separation of bergapten in order to characterize its spasmolytic activity in isolated rat jejunum strips.

MATERIALS AND METHODS

Successful separation of the dichloromethane extract of the fruits of Heracleum leskovii Grossh. was achieved by high-performance countercurrent chromatography (HPCCC) using a two-phase solvent system composed of n-heptane/EtOAc/MeOH/H2O (6:5:6:5, v/v/v/v). The pharmacological assessment of bergapten (0.0001-50 μM) on jejunum smooth muscle strips isolated from rats was conducted under isotonic conditions, following up to three hours of incubation.

RESULTS

The separation method was scaled up six-fold from analytical to semi-preparative conditions, affording bergapten of >99% purity in less than 30 min. This permitted bergapten to be available in quantity for spasmolytic tests on isolated jejunum strips from rats. Bergapten caused myorelaxation of the intestine preparations in the concentration range of 0.0001-1 μM. At higher doses, bergapten caused either relaxation or contraction of the smooth muscle.

DISCUSSION AND CONCLUSION

Bergapten was successfully isolated by rapid HPCCC and its spasmolytic activity was confirmed, thereby providing a preliminary evidence base for the traditional medicine application. The data suggest that bergapten causes no irreversible changes to intestinal tissue.

Scientific basis for use of Pyrus pashia Buch.-Ham. ex D. Don. fruit in gastrointestinal, respiratory and cardiovascular ailments

Background

Pyrus pashia Buch.-Ham. ex D. Don. has been used conventionally by many communities in the Himalayan region for the management of gastrointestinal, respiratory, and vascular complications. Set against this background, this study was carried out to justify the scientific basis to validate folkloric uses of fruits of Pyrus pashia Buch.-Ham. ex D. Don. (Pp.Cr) in traditional systems of medicine.

Methods

The crude ethanol extract of fruits of Pyrus pashia Buch.-Ham. ex D. Don. (Pp.Cr) was tested in vitro on isolated rabbit jejunum, tracheal, and aorta preparations. The responses of tissues were recorded using isotonic transducers coupled with a PowerLab data acquisition system.

Results

The Pp.Cr on application (0.01–5.0 mg/ml) to isolated rabbit jejunum preparation exhibited relaxation through decrease in magnitude and frequency of spontaneous contractions. The Pp.Cr also exerted a relaxant (0.01–5.0 mg/ml) effect on K+(80 mM) induced contractions in isolated rabbit jejunum preparations and caused shifting of the Ca2+ curves (1.0–3.0 mg/ml) toward right in a manner similar to that of verapamil (3μM), possibly suggesting presence of Ca2+ channel blocking activity. Subsequently, Pp.Cr in a concentration-dependent fashion (0.01–10.0 mg/ml) caused relaxation of CCh (1μM) and K+ (80 mM) induced contractions in isolated rabbit tracheal preparations in a manner comparable to that of dicyclomine, suggesting that the observed relaxant effect is likely to be mediated through antimuscarinic and/or Ca2+ channel blocking activities. Moreover, when evaluated against isolated rabbit aortic preparations, the Pp.Cr in concentrations up to 10 mg/ml exhibited a contractile response that was found to be abolished subsequent to pretreatment of isolated tissue preparation with cyproheptadine (1μM), phentolamine (1μM), and losartan (1μM), suggesting that Pp.Cr may have some α-adrenergic, muscarinic, serotonergic, and angiotensin II activities.

Conclusions

The aqueous ethanolic extract of Pyrus pashia (Pp.Cr) exhibited spasmolytic, bronchodilator, and vaso-constrictive activities possibly through different mechanisms. The spasmolytic and bronchodilator activities are likely to be mediated through blockade of Ca2+ channels, while vasoconstrictive activity may be due to presence of a α-adrenergic, muscarinic, serotonergic, and angiotensin II agonistic component.

Bronchodilator, vasodilator and spasmolytic activities of Cymbopogon martinii

Cymbopogon martinii (Cm.Cr) is traditionally used in south Asian communities for the management of multiple ailments including gastrointestinal, respiratory and vascular disorders and the present study was undertaken to validate these folkloric uses. The application of a methanol extract of the plant (Cm.Cr) to isolated rabbit jejunum preparation exhibited relaxation through decrease in magnitude and frequency of spontaneous contractions. The Cm.Cr also exerted relaxant effect on high K(+) (80 mM) induced contractions in isolated rabbit jejunum preparations. The Cm.Cr and its dichloromethane (Cm.Dcm) and aqueous (Cm.Aq) fractions also caused concentration-dependent relaxation in spontaneous and K(+) (80 mM) induced contractions which are comparables to effects produced by verapamil. Cm.Cr caused shifting of the Ca(2+)-curves toward right, suggesting the presence of a Ca(2+) channel blocking activity. Subsequently, Cm.Cr, Cm.Dcm and Cm.Aq caused relaxation of CCh (1 μM) and K(+) (80 mM) induced contractions in isolated rabbit tracheal preparations, suggesting that the observed relaxant effect can be mediated through antimuscarinic and/or Ca(2+) channel blocking activities. Cm.Cr tested against phenylephrine (PE; 1 μM) and K(+) (80 mM) induced contractions exhibited partial relaxation of isolated rabbit aortic preparations. The above-mentioned studies provided a scientific basis for the folkloric use of Cymbopogon martini in the management of multiple ailments in traditional systems of medicines.

Age-dependent effect of obestatin on intestinal contractility in Wistar rats

Obestatin is a 23-amino acid peptide encoded by the ghrelin gene. We have investigated the effect of obestatin on intestinal contractility in rats ranging from the suckling period till adolescence. Duodenal and middle jejunum whole-thickness preparations from neonatal and adult rats were studied in an organ bath, for isometric recording under treatment with obestatin (1μmolL(-1)) in the presence of acetylocholine (ACh), atropine and tetradotoxin (TTX). Both the EFS and ACh-stimulated contractile response, as well as spontaneous contractile activity is age-dependent and specific for the segment of jejunum. Except for the middle jejunum of 7day old rats, treatment with obestatin caused a significant TTX-sensitive increase in the amplitude of EFS-stimulated off-contraction of both intestinal segments studied. Following injection of obestatin, the amplitude of spontaneous contraction in the duodenum increased in 7day old rats. In the middle jejunum, treatment with obestatin significantly increased both the amplitude and frequency of spontaneous contraction in rats till the 28th day of life, whereas in adult rats the observed effect of obestatin was the opposite (P<0.001 and P<0.0001, respectively). The effects of treatment with obestatin on stimulation with increasing doses of ACh were only observed in the preparations from suckling rats. ACh-stimulated contractility in the duodenum was decreased while in the middle jejunum the observed effect was opposite. These results indicate the importance of peripheral obestatin in the cholinergic control of intestinal contractility in both neonatal and adult rats.

Angiotensin IV induced contractions in human jejunal wall musculature in vitro

Angiotensin II (AngII) has been reported to mediate contractile actions in rats and human jejunal wall musculature. However, except for one report showing the angiotensin IV (AngIV) contractile effects on the internal anal sphincter of rats, no data is available describing the action of AngIV on smooth muscle in human small intestine. The aim of this study was to investigate the expression and localization of the enzymes responsible to AngIV formation, as well as the receptor, and to elucidate the contractile function of AngIV in the muscular layer of human jejunum in vitro. Jejunal smooth muscle was taken from 23 patients undergoing Roux-en-Y gastric bypass surgery and was used to record isometric tension in vitro in response to AngIV alone and in the presence of losartan or PD123319. ELISA, western blot and immunohistochemistry were used to investigate the expression and localization of key components for AngIV formation: the enzymes aminopeptidases-A, B, M, and the AngIV receptor insulin-regulated aminopeptidase (IRAP). AngIV elicited concentration-dependent contraction in both longitudinal and circular smooth-muscle preparation. Presence of losartan abolished AngIV-induced contraction, but not PD123319. The main peptide AngII, as well as the enzymes aminopeptidases-A, B and M was detected in all muscle samples. Immunohistochemistry localized the enzymes and IRAP in the myenteric plexus between longitudinal and circular muscle layers. The present study indicates that all enzymes necessary for AngIV formation exist in human jejunal smooth muscle and that the contractile action elicited by AngIV is primarily mediated through the AngII type 1 receptor.

Effects of dehydroeffusol on spasmogen-induced contractile responses of rat intestinal smooth muscles

Dehydroeffusol is a naturally occurring phenanthrene isolated from Juncus effusus. In the context of screening new drugs against gastrointestinal spasms, we investigated its effects on isolated rat jejunum in vitro. Dehydroeffusol (30-90 µM) slightly and transiently enhanced contractions in a concentration-dependent manner but significantly inhibited the contractions induced by KCl (100 mM), (±)-Bay-K8644 (5 µM), pilocarpine (90 µM), and histamine (100 µM). These results show that dehydroeffusol may antagonize the spasmogenic activity of various agents, and therefore, could be a promising agent in the treatment of spasms. Its potential spasmolytic mechanism is also discussed.

[Roles of TRPV1 receptor in electroacupuncture regulating the jejunal motility of mice: an experimental study]

OBJECTIVE

To observe the intestinal movement of transient receptor potential vanilloid 1 or vanilloid receptor 1 (TRPV1) knockout mice after stimulated by electroacupuncture (EA), and to primarily explore the roles of TRPV1 receptor in the jejunal motility regulated by acupuncture.

METHODS

Normal wild-type CL57BL/6 and TRPV1 gene knockout mice were recruited in two groups, the B6 group and the TRPV1 group, 15 in each group. The thermal threshold and the mechanical pain threshold were respectively detected using JL-F digital photo thermal analyzer instrument and ALMEMO2450 machine. The difference between the two thresholds were compared. Meanwhile, a self-made pressure head was placed in the jejunum. The internal pressure was monitored. When the pressure was stable, 2 mA 2/15 Hz EA at Quchi (LI11), Tianshu (ST25), Shangjuxu (ST37), and Dachangshu (BL25) to observe the changes of intestinal pressure value between before and after EA. The curve of internal pressures was recorded.

RESULTS

(1) The stimulation of light/heat and mechanical stimulation were obviously slowed in the TRPV1 group than in the B6 group (P < 0.01). (2) In the intestinal pressure observation experiment, the bowel movement was not obviously seen in the two groups when acupunctured at Quchi (LI11) and Shangjuxu (ST37) (P > 0.05). (3) Acupuncture at Tianshu (ST25) and Dachangshu (BL25) of TRPV1 knockout mice could lead to intestinal movement (P < 0.05), mainly inhibited bowel movement. The changing degree was equivalent to that of B6 mice.

CONCLUSIONS

Under the physiological condition, TRPV1 might be mediated by thermal and mechanical stimulation. But TRPV1 mediated acupuncture effect was quite complex, indicating TRPV1 mice might be one of intestinal movement mediating factors.

[Effects of acupuncture at "Tianshu" (ST 25) on electrical and mechanical motor of jejunum smooth muscles at different phases of the interdigestive migrating motor complex in normal rats]

OBJECTIVE

To observe the effect of acupuncture stimulation of "Tianshu" (ST 25) on electrical and mechanical activities of jejunum smooth muscle at different phases of interdigestive migrating motor complex (MMC) in normal rats, so as to explore its mechanism underlying regulation of intestinal function.

METHODS

A total of 16 adult SD rats were used in the present study. After 18-24 hours' fasting (with free access to water), the rats were subjected into experimental observation. Electromyogram and intestinal mechanical motor were respectively recorded by using implanted metal electrodes and strain gauge (sutured to the serosal surface of the jejunum) and biophysiological amplifier system. Manual acupuncture stimulation was applied to ST 25 for about 1 min at phase I, II and III of MMC, respectively.

RESULTS

Following manual acupuncture stimulation of ST 25, the mean frequencies and amplitudes of both fast and slow waves of electrical activities and muscular contraction tension of the jejunum smooth muscle at phase II and III of MMC were significantly decreased compared to their baseline levels (P < 0.01). No significant changes were found in the mean frequency and amplitude of fast wave of electrical activities of the jejunum smooth muscle at phase I of MMC after acupuncture stimulation of ST 25 (P > 0.05).

CONCLUSION

Acupuncture stimulation of ST 25 can inhibit the jejunum electrical and mechanical activities at phase II and III of MMC in normal rats, probably via somato-sympathetic reflex.

[Effects of acupuncture at "Tianshu" (ST 25) on electro-activity and mechanical motility of migrating motor complex during jejunal digestion period in rats with detached jejunum]

OBJECTIVE

To observe the effects of acupuncture at "Tianshu" (ST 25) on electro-activity and mechanical motility at different phases of migrating motor complex (MMC) during jejunal digestion period in rats with detached jejunum, so as to explore the effect and mechanism of acupuncture on regulating intestinal movement.

METHODS

Sixteen adult SD rats were selected. Electrodes were implanted in the serous membrane of intestinal smooth muscl.e and high-sensitivity sensors of strain gauge were sutured on serosal surface, and then the rat was anesthetized and its jejunum was detached. Electro-acriviry and mechanical motility of jejunal smooth muscle were recorded simultaneously. Acupuncture was applied at "Tianshu" (ST 25) at MMC I , MMCII and MMC III, respectively, to observe its influence on electro-activity and mechanical motility.

RESULTS

At phase of MMC I, there was no obvious change of the fast wave before and after the acupuncture, while the frequency and amplitude of slow wave and mechanical motility were both significantly decreased compared with baseline (P < 0.01). At MMCII-Ill, the frequency and amplitude of fast wave, slow wave and motility were all significantly decreased compared with baseline (P < 0.01). Acupuncture at "Tianshu" (ST 25) had prohibited effects on electro-activity and mechanical motility of jejunal smooth muscle in rats with detached jejunum.

CONCLUSION

Acupuncture at "Tianshu" (ST 25) has obvious prohibited effects on electro-acrivity and mechanical motility at MMC I , MMC II and MMC III time phases in rats with detached jejunum. The possible mechanism is that acupuncture at "Tianshu" (ST 25) could prohibit jejunum movement through reflex path of skin-sympathetic.

Pharmacological basis for the medicinal use of Carissa carandas in constipation and diarrhea

ETHNOPHARMACOLOGICAL RELEVANCE

Carissa carandas Linn. commonly known as "Karaunda" (Apocynaceae) is a popular medicinal herb widely distributed in different parts of Pakistan. In addition to other medicinal uses, Carissa carandas is popular in indigenous system of medicine for its medicinal use in gut motility disorders like, constipation and diarrhea.

OBJECTIVE

This study was planned to provide pharmacological basis to the medicinal use of Carissa carandas in constipation and diarrhea.

MATERIALS AND METHODS

The crude extract of the leaves of Carissa carandas (Cc.Cr) was prepared in methanol and its fractionation was carried out with ethylacetate, petroleum ether and n-butanol. In-vivo studies were conducted on mice, while isolated rabbit jejunum and guinea-pig ileum preparations were used for the in-vitro experiments. The spasmogenic and spasmolytic responses of gut tissues were recorded using isotonic transducers coupled with PowerLab data acquisition system.

RESULTS

The HPLC fingerprints of Cc.Cr, its petroleum (Cc.Pef), ethylacetate (Cc.Eaf) and n-butanol (Cc.Baf) fractions showed the presence of oleanolic acid, ursolic acid, stigmasterol and β-sitosterol. Oral administration of Cc.Cr to mice increased fecal output at lower doses (30 and 50 mg/kg), while it showed protection against castor oil-induced diarrhea at higher doses (300 and 600 mg/kg). In isolated guinea-pig ileum and rabbit jejunum, Cc.Cr and Cc.Baf exhibited stimulatory effect at 0.003-3 mg/ml, which was partially sensitive to atropine or pyrillamine or partially/fully sensitive to atropine+pyrillamine, followed by relaxation at higher tested concentrations, being more potent in rabbit tissues. The ethylacetate fraction (0.1-5 mg/ml) exhibited fully atropine-sensitive contractions in both guinea-pig and rabbit tissues, being more potent in guinea-pig while more efficacious in rabbit tissues. However, the petroleum fraction (0.003-1.0 mg/ml) showed only spasmolytic activity in spontaneously contracting rabbit tissues, similar to nifedipine. In guinea-tissue, Cc.Pef did not cause any stimulant effect. When studied against high K(+) (80 mM)-induced contraction, the crude extract and its fractions caused a dose-dependent inhibition, with the following order of potency: Cc.Pef>Cc.Eaf>Cc.Cr≥Cc.Baf, similar to nifedipine indicating Ca(++) channel antagonist like activity, which was further confirmed when the plant extract displaced Ca(++) curves to the right with suppression of maximum effect similar to that of nifedipine.

CONCLUSION

This study demonstrates that the crude extract of Carissa carandas possesses a gut-stimulatory effect mediated primarily through the activation of muscarinic and histaminergic receptors while its spasmolytic effect was mediated possibly through Ca(++) antagonist pathway. Thus, this study provides a clear evidence for the dual effectiveness of Carissa carandas in constipation and diarrhea, thus validating its medicinal use.

In vitro exposure to Escherichia coli decreases ion conductance in the jejunal epithelium of broiler chickens

Escherichia coli (E. coli) infections are very widespread in poultry. However, little is known about the interaction between the intestinal epithelium and E. coli in chickens. Therefore, the effects of avian non-pathogenic and avian pathogenic Escherichia coli (APEC) on the intestinal function of broiler chickens were investigated by measuring the electrogenic ion transport across the isolated jejunal mucosa. In addition, the intestinal epithelial responses to cholera toxin, histamine and carbamoylcholine (carbachol) were evaluated following an E. coli exposure. Jejunal tissues from 5-week-old broilers were exposed to 6×10(8) CFU/mL of either avian non-pathogenic E. coli IMT11322 (Ont:H16) or avian pathogenic E. coli IMT4529 (O24:H4) in Ussing chambers and electrophysiological variables were monitored for 1 h. After incubation with E. coli for 1 h, either cholera toxin (1 mg/L), histamine (100 μM) or carbachol (100 μM) were added to the incubation medium. Both strains of avian E. coli (non-pathogenic and pathogenic) reduced epithelial ion conductance (Gt) and short-circuit current (Isc). The decrease in ion conductance after exposure to avian pathogenic E. coli was, at least, partly reversed by the histamine or carbachol treatment. Serosal histamine application produced no significant changes in the Isc in any tissues. Only the uninfected control tissues responded significantly to carbachol with an increase of Isc, while the response to carbachol was blunted to non-significant values in infected tissues. Together, these data may explain why chickens rarely respond to intestinal infections with overt secretory diarrhea. Instead, the immediate response to intestinal E. coli infections appears to be a tightening of the epithelial barrier.

The bioelectrical basis and validity of gastrointestinal extracellular slow wave recordings

  Gastrointestinal extracellular recordings have been a core technique in motility research for a century. However, the bioelectrical basis of extracellular data has recently been challenged by claims that these techniques preferentially assay movement artifacts, cannot reproduce the underlying slow wave kinetics, and misrepresent the true slow wave frequency. These claims motivated this joint experimental-theoretical study, which aimed to define the sources and validity of extracellular potentials. In vivo extracellular recordings and video capture were performed in the porcine jejunum, before and after intra-arterial nifedipine administration. Gastric extracellular recordings were recorded simultaneously using conventional serosal contact and suction electrodes, and biphasic and monophasic extracellular potentials were simulated in a biophysical model. Contractions were abolished by nifedipine, but extracellular slow waves persisted, with unchanged amplitude, downstroke rate, velocity, and downstroke width (P>0.10 for all), at reduced frequency (24% lower; P=0.03). Simultaneous suction and conventional serosal extracellular recordings were identical in phase (frequency and activation-recovery interval), but varied in morphology (monophasic vs. biphasic; downstroke rate and amplitude: P<0.0001). Simulations demonstrated the field contribution of current flow to extracellular potential and quantified the effects of localised depolarisation due to suction pressure on extracellular potential morphology. In sum, these results demonstrate that gastrointestinal extracellular slow wave recordings cannot be explained by motion artifacts, and are of a bioelectrical origin that is highly consistent with the underlying biophysics of slow wave propagation. Motion suppression is shown to be unnecessary as a routine control in in vivo extracellular studies, supporting the validity of the extant gastrointestinal extracellular literature.

Bronchodilator, vasodilator and spasmolytic activities of methanolic extract of Myrtus communis L

The present study was undertaken to validate some of the folkloric claims about the effectiveness of the use of a Myrtus communis L. crude methanol extract (Mc.Cr) in gastrointestinal, respiratory and vascular diseases. Mc.Cr caused complete relaxation of spontaneous and K⁺ (80 mM)-induced contractions in isolated rabbit jejunum. It caused right ward parallel shift of calcium concentration response curves. Mc.Cr exhibited relaxant effect on CCh- and K⁺ (80 mM)-induced contractions in isolated rabbit tracheal preparations. Furthermore, Mc.Cr caused relaxation of phenylephrine (1 μM)- and K⁺ (80 mM)-induced contractions in isolated rabbit aorta preparations. These effects were similar to verapamil, a standard calcium channel blocker. These findings could be the basis for explaining the spasmolytic, bronchodilator and vasodilator activities of the extract, through a possible calcium channel blocking activity.

Does different approach during pancreatoduodenectomy influence intestinal migrating myoelectrical complex recovery? Study in experimental pig model

It is said that leaving intact the functional motor unit of the pylorus leads to better gastric emptying and reduces postoperative upper gut motility disturbances. However, despite obvious different surgical approach, both major pancreatoduodenectomies lead to substantial myoelectrical dysfunctions. The latter are not efficiently recognized. We compared Whipple and Longmire-Traverso procedures in terms of electromyography patterns of the upper jejunum musculature and the density of Cajal cells network. Twelve male weaned pigs underwent surgery first to implant bipolar electrodes and telemetry transmitters for continuous electromyography recordings and then, after 1 week recovery, to create Whipple (n=6) and Longmire-Traverso (n=6) pancreatoduodenectomies. The first myoelectric activity was already registered 1-2 hours after both operations. Time to first regular patterns of migrating myoelectrical complex activity was significantly longer in the Whipple than in the Longmire-Traverso group (68.2±12.9 versus 27.8±51 hours, p=0.002). However, the restored patterns were substantially disturbed in both groups. Namely, after Longmire-Traverso operation, migrating myoelectrical complex cycles were very often and significantly shorter versus control ones, with reverse migration in the area of anastomosis while after Whipple procedure migrating myoelectrical complex cycles were less frequent and of short duration, significantly shorter in comparison even with Longmire-Traverso group. Cajal cells network in the vicinity of anastomosis, and distally from it, presented greater destruction after the Whipple operation. In conclusion, the advantage of one of two major pancreatoduodenectomies in terms of myoelectrical activity correctness in upper gut has not been proved in the study.

Inhibitory effects of daidzein on intestinal motility in normal and high contractile states

CONTEXT

Daidzein is a naturally occurring compound and has various health benefits. However, its effects on intestinal smooth muscle contractility remain unknown.

AIMS

The present study was to characterize the effects of daidzein on the contractility of isolated jejunal smooth muscle and its underlying mechanisms.

METHODS

Ex vivo assay was selected as the major method to determine the effects of daidzein on the contractility of isolated jejunal smooth muscle fragment (JSMF).

RESULTS

Daidzein (5-160 µmol/L) inhibited the contractility of JSMF in normal contractile state and in a dose-dependent manner. Daidzein also inhibited the contractility of JSMF induced by ACh, histamine, erythromycin and high Ca²⁺, respectively, and decreased charcoal propulsion in the small intestine in vivo. The inhibitory effects of daidzein were partially blocked by phentolamine or propranolol and were abolished in the presence of varapamil or at Ca²⁺-free assay condition. However, the inhibitory effects of daidzein on jejunal contraction were not significantly influenced by nitric oxide (NO) synthase inhibitor L-NG-nitro-arginine (L-NNA). Daidzein was also found to directly inhibit the phosphorylation and Mg²⁺-ATPase activity of smooth muscle myosin.

DISCUSSION AND CONCLUSION

The results implicated that α- and β-adrenergic receptors were involved in the inhibitory effects produced by daidzein rather than via NO pathway. As a phytoestrogen, daidzein has shown its potential value in relieving the hypercontractility of small intestine.

Mechanisms underlying the antidiarrheal, antispasmodic and bronchodilator activities of Fumaria parviflora and involvement of tissue and species specificity

ETHNOPHARMACOLOGICAL RELEVANCE

In the Greco-Arab (Unani) traditional medicine, Fumaria parviflora Linn. is widely used in hypreractive gut and respiratory disorders including diarrhea, abdominal cramps, indigestion and asthma but scientific studies to provide rational for these medicinal uses are sparse. This study was therefore undertaken to provide ethnopharmacological basis for its medicinal use in diarrhea, abdominal cramps and asthma.

MATERIALS AND METHODS

The in vivo studies were conducted in mice and rats while isolated gut and tracheal preparations of rat, guinea-pig and rabbit were suspended in respective tissue baths to measure the isotonic and isometric responses, using Power Lab electronic recorder.

RESULTS

The aqueous-methanol extract of Fumaria parviflora (Fp.Cr) protected against diarrhea caused by castor oil in rats and mice, similar to loperamide and dicyclomine, and bronchospasm caused by carbachol (CCh) in rats, similar to aminophylline. In the in vitro studies, Fp.Cr relaxed CCh and isotonic high K(+) physiological salts solutions-induced contractions in jejunum, ileum and tracheal preparations of rat, guinea-pig and rabbit. Fp.Cr was predominately more potent against CCh than isotonic high K(+) solutions-induced contractions, similar to dicyclomine, suggesting the presence of anticholinergic and calcium channel blocking (CCB) activities, which were confirmed when Fp.Cr shifted the CCh and Ca(2+) concentration-response curves, constructed in rat ileum and trachea, towards right. Among intestinal preparations from various species, both anticholinergic and CCB effects of Fp.Cr were exhibited at lower concentrations in rat than the other species. In tracheal preparations, Fp.Cr was the most potent in its CCB effect in rabbit. Within species, CCB effect of Fp.Cr was produced at lower concentrations in rat jejunum than ileum and trachea, whereas, anticholinergic effect was produced at higher concentration in rat trachea than intestine.

CONCLUSION

This study, showing the presence of antidiarrheal, antispasmodic and bronchodilator activities in Fumaria parviflora possibly mediated through dual blockade of muscarinic receptors and Ca(2+) channels, provides sound basis for its medicinal uses in diarrhea, abdominal cramps and may be used as bronchodilator in asthma. Species and tissue-dependency of these effects underscores the importance of utilizing multiple tissues and species to get more meaningful results.