Jejunum Strips Research Articles

Modulation of chicken gut contractility by Melissa officinalis—ex vivo study

Melissa officinalis (lemon balm) has a long history of being used in traditional medicine for the treatment of gastrointestinal tract disorders in human thanks to its spasmolytic and stress reducing effects. These pharmacological properties have been confirmed in laboratory animals. Unfortunately, in the case of veterinary medicine, the effect of lemon balm on gut contractility has been never subjected to a detailed investigation. On the other hand, there is urgent need of new drugs that could be safely used in animals for both, causative and symptomatic treatment. In broiler chicken, one of the major health concerns includes gastrointestinal disorders with gut hypermotility. Thus, it is crucial to verify the potential utility of Melissa officinalis extract in gastrointestinal dysmotilities. The aim of the study was to analyze the effect of lemon balm extract and some of its active ingredients on chicken intestine motility. The study was performed on isolated proximal and distal jejunum preparations collected from broiler chicken which underwent routine slaughter procedure. The effect of lemon balm and 3 phenolic acids (rosmarinic, chlorogenic, and lithospermic) was verified under isometric conditions, toward spontaneous and acetylcholine (ACh)-induced smooth muscle activity. Surprisingly, M. officinalis turned out to be rather a myocontractile agent as it increased ACh-provoked contractility of proximal and distal jejunum strips and also intensified the spontaneous activity of distal jejunum. Only in the case of proximal intestine lemon balm extract diminished the force of spontaneous motoric activity up to approx. Sixty-seven percent of the control conditions. None of the tested phenolic acids displayed analog effect with the whole plant extract. In fact in the case of ACh-induced contractility, the acids had the opposite, that is, myorelaxant, effect than the extract, with a small exception of lithospermic acid in distal jejunum. Thus, it is impossible to assign one or more individual constituents to the effect of the whole Melissa officinalis extract. The obtained results do not support the use of lemon balm extract in broiler diseases which are accompanied by gut motility disturbances, including diarrhea.

Butyrlycholine esterase inhibitory activity and effects of extracts (fruit, bark and leaf) from Zanthoxylum armatum DC in gut, airways and vascular smooth muscles

BackgroundFruit, bark and leaves of Zanthoxylum armatum DC are popular remedies for gastrointestinal, cardiovascular and respiratory disorders in the subcontinent traditional practices. The aim of the study was to individually probe the profile of methanol extracts from three different parts of Zanthoxylum armatum.MethodsThe ex-vivo muscle relaxant effects of extracts were assessed in the isolated intestine, trachea and thoracic aortic rings and were compared with the positive controls and CRC were constructed. The anti-diarrheal effect of extracts was evaluated in mice by inducing diarrhea with castor oil. The extracts were also studied for acute toxicity and butyrylcholine esterase inhibition.ResultsThe extracts from fruit, bark and leaves of Z. armatum showed inhibitory effect against the butyrylcholine esterase enzyme with percent inhibition of 50.75 ± 1.23, 82.57 ± 1.33, and 37.52 ± 1.11respectively, compared to standard serine (IC50: 0.04 ± 0.001 μmol/L). The fruit and bark extracts provided 75, and 52% diarrheal protection, compared to verapamil (96%). In isolated rabbit jejunum strips, increasing addition of the extracts inhibited the spontaneous and high K+ precontractions with EC50 values of 0.71 and 3 mg/mL for fruit, EC50 values of 0.61 and 0.5 mg/mL for bark, EC50 0.81 and 3.1 mg/mL for leaves, like verapamil. The extracts induced a concentration-dependent relaxation of the carbachol (1 μM) and high K+ (80 mM) precontractions with EC50 values of 2.4 and 0.9 mg/mL for fruit, EC50 values of 1.2 and 3 for leaves. The bark extract was equipotent against both contractions with EC50 3.1 and 0.7 mg/mL, respectively. In the aortic rings, the fruit extract completely relaxed the phenylephrine (1 μM)-induced contractions with (EC50 value = 0.8 mg/ml) and a partial inhibition of high K+ induced contractions. The leaves extract completely relaxed the aortic contractions with (EC50 values = 1.0 and 8.5 mg/ml). The extracts caused no acute toxicity up to 3 g/kg dose.ConclusionsThe experiments revealed that the extracts of aerial parts of Z. armatum have antidiarrheal properties in vivo and showed spasmolytic effect in intestinal and tracheal preparations with possible mechanism involving the blockage of Ca++ channels. These experiments provide enough justification for use of this plant in ethnomedicine in diarrhea, gut and bronchial spasms.

The effect of pyriproxyfen on the motoric activity of rat intestine - In vitro study

The application of pyriproxyfen (PPF) to drinking water and constant exposure of the whole population to this insecticide is an unprecedented action on a world scale and presents a new and serious challenge for toxicology. The aim of the study was to evaluate the potential effect of PPF on the intestine muscle activity. The experiments were performed on isolated duodenum and jejunum strips of rat, in isometric conditions. Doses of PPF in the range of 0.032–100 μM were used in the experiments. The obtained results indicate that PPF affected significantly the spontaneous activity of duodenum and jejunum strips, PPF caused the muscle relaxation when used in the concentration of 0.8 μM and higher. The reaction to acetylcholine (ACh) when PPF preceded or followed ACh application was also reduced. It is demonstrated that the reduction of the contraction caused by ACh was stronger when duodenum strips were preincubated in the presence of PPF solution than in case of ACh-precontracted strips. The first significant reaction of duodenal strips appeared in the presence of PPF in a dose of 0.16 μM and 0.8 μM when the insecticide application preceded and followed ACh treatment, respectively. Besides, the duodenum turned out to be much more susceptible to the tested insecticide than jejunum. Taking into account PPF kinetic data obtained in animals, the observed disturbances were caused by the insecticide used in relatively high concentrations. However, the full risk estimation requires the kinetic data obtained in human, especially from monitoring studies on general population after long-term exposure to PPF.

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.

Antispasmodic effect of selected Citrus flavonoids on rat isolated jejunum specimens

Citrus flavonoids are acknowledged for numerous pharmacological activities, including the myorelaxant effect on various smooth muscles. However, there is no data on their effect on jejunum contractility. Therefore, the aim of the study at hand was to evaluate the impact of hesperetin and diosmetin along with their glycosides on the motoric activity of intestine and to verify the possible mechanism of hesperetin-induced effect. The experiments were performed on rat isolated jejunum strips and were conducted under isometric conditions.Hesperetin and diosmetin, but not hesperidin and diosmin, dose-dependently (10–100µM) and reversibly inhibited acetylcholine (1µM) and KCl (80mM) induced contractile activity. The antispasmodic effect of hesperetin was partially blocked by 4-aminopyridine (100µM), glibenclamide (100µM) and NG-nitro-L-arginine methyl ester (L-NAME, 100µM). By contrast, apamin (0.1µM), tetraethylammonium (500µM) and methylene blue (10µM) did not affect the magnitude of hesperetin-induced myorelaxant effect. Indomethacin (10µM) increased the force of hesperetin-evoked reaction.In conclusion, hesperetin and diosmetin are potent myorelaxant agents. The antispasmodic effect of hesperetin is partially mediated by fast current low-voltage activated K+ channels, voltage-independent K+ channels and involves the nitric oxide pathway. Finally, hesperetin shows a synergistic effect with indomethacin towards jejunal KCl-precontracted smooth muscle.

Ion channels’ disturbances are responsible for biphasic jejunum strips reaction to glyphosate

Ion channels’ disturbances are responsible for biphasic jejunum strips reaction to glyphosate

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.

Effect of Imperatorin on the Spontaneous Motor Activity of Rat Isolated Jejunum Strips.

Imperatorin, a psoralen-type furanocoumarin, is a potent myorelaxant agent acting as a calcium antagonist on vascular smooth muscle. Its effects on other types of smooth muscle remain unknown. Therefore, the aim of this study was to investigate the hypothesized myorelaxant effect of imperatorin on gut motor activity and, possibly, to define the underlying mechanism of action. Imperatorin was made available for pharmacological studies from the fruits of the widely available Angelica officinalis through the application of high-performance countercurrent chromatography (HPCCC). Imperatorin generated reversible relaxation of jejunum strips dose-dependently (1–100 μM). At 25 and 50 μM, imperatorin caused relaxation comparable to the strength of the reaction induced by isoproterenol (Isop) at 0.1 μM. The observed response resulted neither from the activation of soluble guanylate cyclase, nor from β-adrenoreceptor involvement, nor from Ca2+-activated potassium channels. Imperatorin relaxed intestine strips precontracted with high potassium concentration, attenuated the force and duration of K+-induced contractions, and modulated the response of jejunum strips to acetylcholine. The results suggest that imperatorin probably interacts with various Ca2+ influx pathways in intestine smooth muscle. The types of some calcium channels involved in the activity of imperatorin will be examined in a subsequent study.

Glyphosate affects the spontaneous motoric activity of intestine at very low doses – In vitro study

Glyphosate is an active substance of the most popular herbicides worldwide. Its common use results from the belief that it affects exclusively plants. However, studies on glyphosate and its trade formulations reveal that it causes numerous morphological, physiological and biochemical disturbances in cells and organisms of animals, including mammals. Due to the fact that shortly after oral exposure glyphosate is detected in the highest amount in small intestine, the aim of this study was to evaluate the effect of this compound on the spontaneous motoric activity of intestine under in vitro conditions. The experiments were conducted on rat jejunum strips under isotonic conditions. The strips were incubated in buffered (pH 7.35) and non-buffered (pH 5.2) glyphosate solutions ranged from 0.003 to 1.7g/L. The results indicate that glyphosate applied in buffered solution affects significantly the spontaneous motoric activity of rat isolated jejunum strips. The muscle response is biphasic (miorelaxation accompanied by contraction). The contraction is observed already at a dose of 0.003g/L and the first significant biphasic reaction at a dose of 0.014g/L. The incubation of jejunum strips with glyphosate in non-buffered solution (pH 5.2) results in a different reaction. The smooth muscle undergoes only persistent relaxation, which is stronger than the response to glyphosate solution in pH 7.35. Motility disturbances are also observed after glyphosate removal from the incubation solution. The gathered data suggests that glyphosate impairs gastrointestinal strips’ motility at concentration that are noticed in human exposed to non-toxic doses of glyphosate.

Anti-diarrhoeal activity of methanol extract of Santalum album L. in mice and gastrointestinal effect on the contraction of isolated jejunum in rats

Ethnopharmacological relevanceSantalum album L., namely Sandalwood, honored as “Green Gold”, is a traditional Chinese herb which has the effects of anti-diarrhoeal and antibacterial activity. But there is limit scientific study on its activity and mechanism in gastrointestinal disorders. Materials and methodsin vivo, after intragastric administration, the methanol extract of Sandalwood (SE) (200, 400 and 800mg/kg) were studied in castor oil-induced diarrhoea mice. By the test of small intestinal hyperfunction induced by neostigmine, SE was studied on gastrointestinal transit including gastric emptying and small intestinal motility. Meanwhile, in vitro, the effects of SE (0.02, 0.05, 0.1, 0.2, 0.3, 0.4mg/mL) on the isolated tissue preparations of rat jejunum were also investigated. The rat jejunum strips were pre-contracted with acetylcholine (Ach; 10−6M), 5-hydroxytryptamine (5-HT, 200μM) or potassium chloride (KCl; 60mM) and tested in the presence of SE. In addition, the possible myogenic effect was analyzed in the pretreatment of the jejunum preparations with SE or verapamil in Ca2+-free high-K+ (60mM) solution containing EDTA. ResultsAt doses of 200, 400 and 800mg/kg, SE showed significant anti-diarrhoeal activity against castor oil-induced diarrhoea as compared with the control. At the same doses, it also inhibited the gastric emptying and small intestinal motility in the mice of which small intestinal hyperfunction induced by neostigmine. It caused inhibitory effects on the spontaneous contraction of rat-isolated jejunum in dose-dependent manner ranging from 0.02 to 0.4mg/mL, and it also relaxed the Ach-induced, 5-HT-induced and K+-induced contractions. SE shifted the Ca2+ concentration–response curves to right, similar to that caused by verapamil (0.025mM). ConclusionsThese findings indicated that SE played a spasmolytic role in gastrointestinal motility which was probably mediated through inhibition of muscarinic receptors, 5-HT receptors and calcium influx. All these results provide pharmacological basis for its clinical use in gastrointestinal tract.

The effect of glyphosate on the spontaneous motoric activity of rat isolated jejunum strips

The effect of glyphosate on the spontaneous motoric activity of rat isolated jejunum strips

The mechanism of intestinal motility in homozygous mutant Ncx/Hox11L.1-deficient mice—a model for intestinal neuronal dysplasia

Homozygous mutant Ncx/Hox11L.1-deficient (Ncx-/-) mice develop mega-ileo-ceco-colon with a caliber change in the proximal colon. This study investigated the mechanism of intestinal motility in these mice. Five-week-old male and female Ncx-/- mice with mega-ileo-ceco-colon (n = 8) were compared with age-matched male BDF1 mice used as controls (n = 8). All mice were sacrificed, and uniform-sized strips of jejunum, ileum, proximal colon, and distal colon were exposed to electrical field stimulation and pretreatment with atropine sulfate, guanethidine, or tetrodotoxin. Contractile responses were recorded and compared. Longitudinal muscle from strips of jejunum and ileum from all mice (BDF1 and Ncx-/-) did not respond to electrical field stimulation, whereas ileal circular muscle contracted in BDF1 mice and contracted and relaxed in Ncx-/- mice. Pretreatment with atropine sulfate and guanethidine inhibited the responses of circular muscle of distal colon and ileum in BDF1 mice significantly (P < .05), but no effect was observed in Ncx-/- mice. In ileum, BDF1 mice have cholinergic and adrenergic dominant contraction patterns, whereas Ncx-/- mice have relaxation-dominant patterns because of nonadrenergic, noncholinergic nerves. Based on this, there would appear to be some kind of variation in the gastrointestinal nerve supply in Ncx-/- mice.

Nitrergic mechanisms mediating inhibitory control of longitudinal smooth muscle contraction in mouse small intestine

Studies using genetic manipulation to investigate mechanisms of control of physiologic function often necessitate mouse models. However, baseline functional analysis of murine small intestinal motility has not been well defined. Our aim was to define nitrergic mechanisms regulating mouse small intestinal longitudinal muscle. Endogenous nitric oxide (NO) is an important neuroregulatory substance mediating inhibition of contractile activity in murine small bowel. Full-thickness muscle strips of jejunum and ileum from C57BL/6 mice (n > or =6 mice) cut in the direction of longitudinal muscle were studied. Numerous conditions of electrical field stimulation (EFS) and effects of exogenous NO and NO donors were studied in the absence or presence of inhibitors of nitric oxide synthase (NOS) and 1H-[1,2,4]-oxadiazaolo-[4,3-a]-quinoxalin-1-one (ODQ), a downstream inhibitor of guanylyl cyclase. EFS induced a frequency-dependent inhibition of contractile activity in both jejunum and ileum (P < 0.05). As the voltage of EFS was increased, inhibition turned to excitation in the jejunum; in contrast, the ileum demonstrated a voltage-dependent increasing inhibition (P < 0.05 each). EFS-induced inhibition was blocked by NOS inhibitors and ODQ. NO donors inhibited spontaneous contractile activity abolished by ODQ. NO appears to be an endogenous inhibitory neurotransmitter in murine longitudinal small bowel muscle. Nitrergic mechanisms mediate inhibitory control of murine longitudinal small intestinal muscle. Differences exist in neuroregulatory control between jejunum and ileum that may be related to their known difference in motor patterns.

Contractile properties of enteric smooth muscle after small bowel transplantation in rats

The effects of small bowel transplantation (SBTx) on the function of enteric smooth muscle are not understood. To study the contractile properties of enteric smooth muscle after SBTx in rats. Five groups of inbred Lewis rats (n > or = 8 each group) were studied: unoperated, naive controls; operated controls 1 week (OC1) and 8 weeks after intestinal transection/reanastomosis of the proximal jejunum and distal ileum; and 1 week (TX1) and 8 weeks (TX8) after syngeneic orthotopic SBTx. Contractile activity of circular muscle strips of jejunum was evaluated in tissue chambers. Spontaneous contractile activity (force per wet weight tissue) increased in TX1, TX8, and OC1 rats (P < or = 0.01). Frequency of contractions doubled in OC1 rats (P < or = 0.001) but was unchanged in the other groups. In the presence of nonadrenergic noncholinergic (NANC) blockade, spontaneous contractile activity increased in TX1 and OC1 (P < or = 0.005) without a change in frequency of contractions. Inhibition of neural activity with tetrodotoxoin increased amplitude and frequency in all groups. Bethanechol (3 x 10(-6) to 3 x 10(-4) mol/L) increased, and norepinephrine (1 x 10(-6) to 1 x 10(-4) mol/L) dose-dependently decreased the amplitude and frequency of contractions in all groups; equi-effective concentrations, however, did not differ among groups. The increase in contractile activity after intestinal transection/reanastomosis is secondary to an increase in frequency of contractions and not amplitude. SBTx increases contractile amplitude of circular muscle due, in part, to downregulation of NANC nerves but not via muscarinic or adrenergic hypersensitivity. These alterations in enteric physiology of intestinal contractile activity may have important implications in clinical SBTx.

Cardiac and renal sympathetic nerve activities during epidural anesthesia in cats

The effects of small bowel transplantation (SBTx) on the function of enteric smooth muscle are not understood. purpose: To study the contractile properties of enteric smooth muscle after SBTx in rats.Five groups of inbred Lewis rats (n ≥8 each group) were studied: unoperated, naive controls; operated controls 1 week (OC1) and 8 weeks after intestinal transection/reanastomosis of the proximal jejunum and distal lleum; and 1 week (TX1) and 8 weeks (TX8) after syngeneic orthotopic SBTx. Contractile activity of circular muscle strips of jejunum was evaluated in tissue chambers. Spontaneous contractile activity (force per wet weight tissue) increased in TX1, TX8, and OC1 rats (P ≤0.01). Frequency of contractions doubled in OC1 rats (P ≤0.001) but was unchanged in the other groups. In the presence of nonadrenergic noncholinergic (NANC) blockade, spontaneous contractile activity increased in TX1 and OC1 (P ≤0.005) without a change in frequency of contractions. Inhibition of neural activity with tetrodotoxoin increased amplitude and frequency in all groups. Bethanechol (3 × 10−6 to 3 x 10mol/L) increased, and norepinephrlne (1 × 10−6 to 1 × 10−4 mol/L) dose-dependently decreased the amplitude and frequency of contractions in all groups; equi-effective concentrations, however, did not differ among groups.The increase in contractile activity after intestinal transection/reanastomosis is secondary to an increase in frequency of contractions and not amplitude. SBTx increases contractile amplitude of circular muscle due, in part, to downregulation of NANC nerves but not via muscarinlc or adrenergic hypersensitivity. These alterations in enteric physiology of intestinal contractile activity may have important implications in clinical SBTx.

Antigen-induced contraction of jejunal smooth muscle in the sensitized rat.

We examined contractility of longitudinal muscle strips of jejunum from control rats and rats infected 34-85 days previously with Trichinella spiralis. Antigen prepared from T. spiralis larvae contracted muscle from previously infected but not control rats. Contraction was specific for the sensitizing agent because antigen from Nippostrongylus brasiliensis did not induce contraction. Contraction was resistant to atropine or tetrodotoxin but was inhibited by the 5-hydroxytryptamine (5-HT) antagonist cyproheptadine and by 5-HT desensitization. Neither histamine antagonists, diphenhydramine (H1-receptor antagonist) or ranitidine (H2-receptor antagonist), nor indomethacin, a prostaglandin synthase inhibitor, influenced the antigen response. In Trichinella-infected rats there was a significant increase in mast cell number in the muscle layers, and the contraction induced by T. spiralis antigen was inhibited by the mast cell stabilizer doxantrazole. In addition, anti-rat immunoglobulin E serum, compound 48/80, and concanavalin A each contracted muscles from rats previously infected with T. spiralis. These results are consistent with the hypothesis that T. spiralis infection leads to mast cell proliferation in the muscle layers and that subsequent exposure to antigen results in mast cell degranulation, 5-HT release, and contraction of smooth muscle.