Effects of Cirsium palustre Extracts and Their Main Flavonoids on Colon Motility-An Ex Vivo Study

For centuries, various species from the genus Cirsium have been utilized in traditional medicine worldwide. A number of ethnopharmacological reports have pointed out that Cirsium plants can be applied to diminish digestive problems. Among them, Cirsium palustre (L.) Scop. (Asteraceae) stands out as a promising herbal drug candidate because its constituents exhibit antimicrobial and antioxidant potential, as evidenced by ethnopharmacological reports. As a result, the species is particularly intriguing as an adjunctive therapy for functional gastrointestinal and motility disorders. Our research goal was to verify how the extracts, fractions, and main flavonoids of C. palustre affect colon contractility under ex vivo conditions. An alternative model with porcine-isolated colon specimens was used to identify the effects of C. palustre preparations and their primary flavonoids. LC-ESI-MS was utilized to evaluate the impacts of methanol (CP1), methanolic 50% (CP2), and aqueous (CP3) extracts as well as diethyl ether (CP4), ethyl acetate (CP5), and n-butanol (CP6) fractions. Additionally, the impacts of four flavonoids, apigenin (API), luteolin (LUT), apigenin 7-O-glucuronide (A7GLC), and chrysoeriol (CHRY), on spontaneous and acetylcholine-induced motility were assessed under isometric conditions. The results showed that C. palustre extracts, fractions, and their flavonoids exhibit potent motility-regulating effects on colonic smooth muscle. The motility-regulating effect was observed on spontaneous and acetylcholine-induced contractility. All extracts and fractions exhibited an enhancement of the spontaneous contractility of colonic smooth muscle. For acetylcholine-induced activity, CP1, CP2, and CP4 caused a spasmolytic effect, and CP5 and CP6 had a spasmodic effect. LUT and CHRY showed a spasmolytic effect in the case of spontaneous and acetylcholine-induced activity. In contrast, API and A7GLC showed a contractile effect in the case of spontaneous and pharmacologically induced activity. Considering the results obtained from the study, C. palustre could potentially provide benefits in the treatment of functional gastrointestinal disorders characterized by hypomotility and hypermotility.

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.

Morphometry and topography of the coronary ostia in the dog

Introduction

The purpose of this study was to perform a morphometric examination of the coronary ostia, including their location in the area of the aortic sinuses, and to describe variations in ostia structure in the domestic dog.

Material and Methods

The study was conducted on the hearts of 91 pedigree dogs of both sexes, aged 1 to 18 years (median 9 years), with a body weight from 1.2 to 65 kg (median 20.7 kg). Morphometric examinations of the coronary ostia were performed in the studied individuals, and the location of the structures in relation to the intercommissural lines was determined.

Results

Three types of location of the coronary ostia were distinguished, i.e. below the intercommissural line (type I), on the intercommissural line (type II), and above the intercommissural line (type III). In the studied dogs, the most common location of the ostia was type I - found in the left coronary artery of 74/91 dogs (81%) and in the right coronary artery of 42/91 dogs (46%). Morphological variations were shown in 36/91 dogs (40%) in the structure of the coronary ostia, including the presence of accessory ostia. The most common variation was the presence of an accessory ostium near the ostium of the right coronary artery, which was found in 28/91 dogs (31%).

Conclusion

The results may be useful in developing standards for procedures to replace the whole or part of the aortic valve and repair the coronary artery.

Diclofenac and dexamethasone modulate the effect of cannabidiol on the rat colon motility ex vivo

Introduction

Due to the growing interest in the use of cannabinoids in supportive therapies, they are increasingly used together with anti-inflammatory drugs. Cannabinoids inhibit gastrointestinal motility, while steroidal and nonsteroidal anti-inflammatory drugs influence motility in other ways. The aim of the research was to study the interactions between cannabidiol (CBD) and these two classes of anti-inflammatory drugs in the context of gastrointestinal motility. Dexamethasone (DEX) was selected as a steroidal drug and diclofenac (DCF) as a nonsteroidal counterpart.

Material and Methods

The experiments were performed on isolated rat colon strips in isometric conditions. The contractile response to acetylcholine (ACh) (1 μM) was measured with no substance applied as a control value and was measured after application of CBD (80 μM), DEX (100 μM), DCF (100 μM), or a combination of these substances.

Results

Cannabidiol strongly inhibited intestinal motility mediated by ACh application, DCF inhibited it non-significantly, while DEX intensified it. When CBD was co-administered with DEX, the combination inhibited intestinal motility non-significantly relative to the ACh-only control. Co-administration of CBD with DCF inhibited motility more than when these substances were administered separately.

Conclusion

Inhibition of the intestinal response to ACh is likely due to the synergistic effect of CBD and endogenous cannabinoids. Dexamethasone lessened the inhibitory effect of CBD, likely because of diminished availability of the arachidonic acid necessary for endogenous cannabinoid synthesis. However, diclofenac may increase endogenous cannabinoid synthesis, because of the greater availability of arachidonic acid caused by DCF blocking the cyclooxygenation pathway.

Phytogenic Compounds for Enhancing Intestinal Barrier Function in Poultry-A Review

After the European Union ban of antibiotic growth promoters, works on different methods of improving gut health have intensified. The poultry industry is struggling with problems that were previously controlled by antibiotic growth promoters, therefore the search for optimal solutions continues. Simultaneously, there is also increasing social pressure to minimize the use of antibiotics and replace them with alternative feed additives. A variety of available alternatives is considered safe by consumers, among which phytogenics play a significant role. However, there are still some limitations that need to be considered. The most questionable are the issues related to bioavailability, metabolism of plant derivatives in birds, and the difficulty of standardizing commercial products. There is still a need for more evidence-based recommendations for the use of phytogenics in livestock. On the other hand, a positive influence of phytogenic compounds on the health of poultry has been previously described by many researchers and practical application of these compounds has auspicious perspectives in poultry production. Supplementation with phytogenic feed additives has been shown to protect birds from various environmental threats leading to impaired intestinal barrier function. Phytogenic feed additives have the potential to improve the overall structure of intestinal mucosa as well as gut barrier function on a molecular level. Recognition of the phytogenics' effect on the components of the intestinal barrier may enable the selection of the most suitable ones to alleviate negative effects of different agents. This review aims to summarize current knowledge of the influence of various phytogenic constituents on the intestinal barrier and health of poultry.

Evaluation of the effects of Bidens tripartita extracts and their main constituents on intestinal motility - An ex vivo study

ETHNOPHARMACOLOGICAL RELEVANCE

Based on traditional medicine, infusions of Bidens species (Asteraceae) have been successfully used in the treatment of acute and chronic enteritis. Additionally, ethnopharmacological reports demonstrating the gastrointestinal, gastroprotective, anti-inflammatory, antiulcerogenic and immunomodulatory potency of Bidens tripartita Linn. (Asteraceae) and its constituents make the plant a particularly interesting herbal drug candidate for the supportive treatment of functional gastrointestinal and motility disorders.

AIM OF THE STUDY

The study aimed to verify the effects of B. tripartita and its main flavonoid constituents on intestinal contractility patterns under ex vivo conditions.

MATERIALS AND METHODS

The effects of B. tripartita preparations and their main flavonoids were identified using an alternative model of porcine isolated jejunum specimens. Using LC-ESI-MS, the effects of six different standardized extracts, aqueous (BT1), methanolic 50% (BT2), methanolic (BT3), diethyl ether (BT4), ethyl acetate (BT5) and butanol (BT6) (0.001-0.1 mg/mL), as well as three pure isolated flavonoids, luteolin (LUT), cynaroside (CYN) and flavanomarein (ION) (0.001-100 μM), were evaluated towards spontaneous and acetylcholine-induced motility.

RESULTS AND CONCLUSION

s: The results showed the potent prokinetic effects of the B. tripartita extracts and their flavonoids on jejunum smooth muscle. The myocontractile effect was observed on both spontaneous and acetylcholine-induced contractility. There were no substantial differences in the magnitude of myocontractile effects between all six extracts with the exception of the butanol extract which seemed to have a slightly stronger prokinetic effect than the other extracts. The use of extracts at the highest tested concentrations provoked an approximately 1.5-fold increased reaction to acetylcholine compared to the control treatment. The myocontractile effect of the single flavonoids justifies the hypothesis that these secondary metabolites are responsible for the prokinetic activity of all the tested extracts. Among the tested flavonoids, CYN appeared to be the most potent ingredient of B. tripartita; the increase in the response to acetylcholine in the presence of this compound exceeded 250% of the control reaction. In view of the obtained results, the range of functional gastrointestinal disorders in which B. tripartita could be expected to bring benefits include the predominantly constipative phases of irritable bowel syndrome and dyspeptic complaints in which treatment protocols usually involve gastroprokinetics.

The impact of chlorophyllin on deoxynivalenol transport across jejunum mucosa explants obtained from adult pigs

Regardless of the efforts put into preventing or reducing fungal growth, extensive mycotoxin contamination has been reported in animal feeds. In the case of pigs, one of the mycotoxins of major concern is deoxynivalenol (DON). The use of adsorbents as feed additives represents one of the strategies to control mycotoxins' contamination in feedstuff. Therefore, the aim of the study was to verify the ability of chlorophyllin (CHL) to reduce the absorption rate of DON in swine mucosa explants. Intestine was obtained from routinely slaughtered adult pigs. The mucosa explants were studied by means of Ussing chamber technique. The effect of DON (10 and 30 μg/ml) on mucosa viability and permeability and CHL (100 μg/ml) impact on DON (30 μg/ml) absorption was verified. The results revealed that mucosa explants isolated from adult animals remained unaffected for 90 min in the presence of DON in the lower concentration (10 μg/ml). Mycotoxin in the higher dose (30 μg/ml) increased mucosa permeability (decreased transepithelial electrical resistance value) and enhanced paracellular transport of lucifer yellow and mannitol but did not affect lactate dehydrogenase leakage. The introduction of CHL neither diminished the absorption rate of DON across swine mucosa explants nor prevented the toxic effects of DON on intestine. In conclusion, the results confirm the negative effect of DON on pig jejunum mucosa. However, the toxic effect of DON was observed only when it was used in relatively high doses. A promising adsorbent agent, CHL, failed to reduce the intensity of DON transport across intestine under in vitro conditions.

Modulations of bovine hepatic microsomal metabolism of benzimidazoles by secondary plant metabolites

The study was aimed to estimate the effect of plant secondary metabolites present in ruminants diet and phytogenic feed additives on liver microsomal metabolism of albendazole and fenbendazole. The selected phytocompounds comprised of flavonoids (apigenin, quercetin) and saponins (hederagenin, medicagenic acid). The experiments were performed on liver microsomal fraction obtained from routinely slaughtered cows. The intensity of albendazole and fenbendazole metabolism in the presence of flavonoids and saponins was analyzed in equimolar concentration (100 μM). The obtained results revealed that both flavonoids and saponins intensify the metabolism of albendazole and fenbendazole in bovine microsomes. In the case of albendazole, apigenin and quercetin doubled the amount of degraded drug and the amount of produced albendazole sulfoxide. Additionally, both flavonoids increased the amount of produced albendazole sulfone. Saponins, hederagenin, and medicagenic acid intensified the degradation of albendazole (1.8-fold) and the production of albendazole sulfoxide (twofold). Medicagenic acid inhibited the production of albendazole sulfone. In the case of fenbendazole, the degradation of the drug and the production of oxfendazole were increased four and five times in the presence of saponins and flavonoids, respectively. The enhancement of benzimidazoles' metabolism caused by the studied plant metabolites could change pharmacokinetics and the efficacy of benzimidazoles' treatment in cattle.

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.

Interactions between erythromycin, flunixin meglumine, levamisole and plant secondary metabolites towards bovine gastrointestinal motility-in vitro study

Continued ingestion of plant secondary metabolites by ruminants can provoke pharmacological interactions with pharmaceutical agents used in animals. As some drugs and phytocompounds affect smooth muscle activity, the aim of this study was to verify the possible interaction between selected pharmaceutical agents and plant secondary metabolites towards bovine gastrointestinal motility. The interactions between phytocompounds-apigenin, quercetin, hederagenin, medicagenic acid-and medicines-erythromycin, flunixin meglumine and levamisole-were evaluated on bovine isolated abomasal and duodenal specimens obtained from routinely slaughtered cows. The obtained results confirmed the contractile effect of all three drugs used solely. Hederagenin and medicagenic acid (0.001 μM) enhanced the contractile effect of levamisole. Hederagenin additionally increased the impact of erythromycin. Both saponins (100 μM) showed synergistic effects with all tested pharmaceuticals. Apigenin and quercetin (0.001 μM) intensified the contractile response induced by erythromycin and levamisole. Moreover, both flavonoids (100 μM) showed an antagonistic interaction with all tested drugs which in that situation were devoid of the prokinetic effect. To conclude, plant metabolic metabolites such as saponins and flavonoids are potent modifiers of the effect of drugs towards gut motility. The synergy observed between phytocompounds and selected medicines can be beneficial in the treatment of cows with hypomotility disorders.

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.

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.

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 1.7 g/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 0.003 g/L and the first significant biphasic reaction at a dose of 0.014 g/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.

Participation of extracellular calcium in α-hederin-induced contractions of rat isolated stomach strips

ETHNOPHARMACOLOGICAL RELEVANCE

The dry extract of Hedera helix leaves, due to its secretolytic and antispasmodic effects, is commonly used to produce pharmaceuticals applied in case of cough and other respiratory symptoms. The results of some in vitro studies as well as the clinical signs of poisoning caused by Hedera helix suggest however strong contractile effect on smooth muscle. In order to clarify the impact of α-hederin (the main active agent of ivy extract) on smooth muscle, the origin of activated calcium involved in α-hederin-induced contraction of gastric smooth muscle preparations was studied.

MATERIALS AND METHODS

The study was carried out on rat isolated stomach corpus and fundus strips, under isotonic conditions. The effect of α-hederin (100 μM) on smooth muscle preparations was measured before and after the treatment with verapamil during the incubation in modified Krebs-Henseleit solution (M K-HS). Besides, the effect of saponin was measured during the incubation of preparation in Ca2+-free modified Krebs-Henseleit solution or Ca2+-free EGTA-containing modified Krebs-Henseleit solution.

RESULTS

The obtained results revealed that the application of verapamil significantly inhibited the reaction evoked by α-hederin. The incubation of stomach strips in calcium-free modified Krebs-Henseleit solution did not change the force of the observed contraction in comparison to the reaction of the preparations incubated in regular incubation solution (M K-HS). In contrary, the replacement of M K-HS by calcium-free chelator-containing solution inhibited totally the reaction to α-hederin.

CONCLUSIONS

The results indicated that α-hederin-induced contraction results from the influx of calcium which is located in intercellular spaces or bound to the outside of the cell membrane. The Ca2+ influx occurs predominantly through voltage-dependent calcium channels of L-type.

Participation of cholinergic pathways in α-hederin-induced contraction of rat isolated stomach strips

The dry extract of Hedra helix leaves and its main active compounds, predominantly α-hederin and hederacoside C, has been traditionally believed to act spasmolytic. However, it has been recently proved that both, the extract of ivy and triterpenoid saponins, exhibit strong contractile effect on rat isolated stomach smooth muscle strips. It turned out that the most potent contractile agent isolated from the extract of ivy leaves is α-hederin. Thus, it seems reasonable to estimate the mechanism of the contractile effect of this saponin. The presented study was aimed at verifying the participation of cholinergic pathways (muscarinic and nicotine receptors) in α-hederin-induced contraction. The experiments were carried out on rat isolated stomach corpus and fundus strips under isotonic conditions. The preparations were preincubated with either atropine or hexamethonium and then exposed to α-hederin. All results are expressed as the percentage of the response to acetylcholine - a reference contractile agent. The obtained results revealed that the pretreatment of isolated stomach strips (corpus and fundus) with atropine neither prevented nor remarkably reduced the reaction of the preparations to α-hederin. Similarly, if the application of saponin was preceded by the administration of hexamethonium, the strength of the contraction of stomach fundus strips induced by α-hederin was not modified. Concluding, it can be assumed that the cholinergic pathways do not participate in α-hederin-evoked contraction of rat isolated stomach preparations.

The effect of the whole extract of common ivy (Hedera helix) leaves and selected active substances on the motoric activity of rat isolated stomach strips

ETHNOPHARMACOLOGICAL RELEVANCE

The long tradition of using the dry extract of Hedera helix (common ivy) leaves in traditional and contemporary alternative medicine caused that many biological and pharmacological studies have been aimed at evaluating the effects of ivy. Some of the results suggest that Hedera helix extract possesses bronchodilatatory and antispasmodic activity. On the other hand, the symptoms of ivy intoxication in human and animals, as well as adverse-reactions observed during the therapy with ivy-based pharmaceuticals, indicate rather stimulant effect of the plant on smooth muscle. Thus, the aim of this study was to evaluate the effect of two main active substances extracted from the plant (α-hederin and hederacoside C) and the whole dry extract of Hedera helix on the gut motility.

MATERIALS AND METHODS

The experiments were carried out on isolated stomach corpus and fundus strips. The tissues were isolated from rats. The experiments were performed in isotonic conditions. The results are expressed as the percent of the reaction caused by a reference contractile substance, acetylcholine.

RESULTS AND CONCLUSIONS

The obtained results revealed that α-hederin applied in the concentration ranged from 25 to 320μM significantly changed the spontaneous motoric activity of rat stomach smooth muscle. The observed reaction had always the same character, a contraction, and its force was concentration dependent. The second tested saponin, hederacoside C, did not alter the motility of rat isolated stomach corpus and fundus strips when administered in the concentration up to 100 μM, however, if applied in the concentration of 350 μM it induced a remarkable concentration of smooth muscle. Eventually, the whole extract of Hedera helix in a dose containing 60 μM of hederacoside C produced a strong contraction which strength was comparable with the reaction generated by acetylcholine. According to the results, it is very likely that α-hederin, but not hederacoside C contributes to the contractile response of isolated stomach corpus and fundus strips to the application of Hedera helix leaves' extract.

Evaluation of the time-stability of an alternative research model based on isolated rat gastrointestinal strips

Experiments were performed on rat isolated gastrointestinal (GI) strips. The study was carried out in isotonic conditions during a long-term (5-8 h) incubation in modified Krebs-Henseleit solution, (M K-HS) at 37 degrees C. The reaction of GI muscle strips to acetylcholine (ACh) and histological images of the tissues strips were studied. Additionally, spontaneous motor activity of the jejunum strips was evaluated. The obtained results indicate that as well the spontaneous motility as the response of jejunum muscle strips to acetylcholine and the histological structure of the preparations changed throughout the incubation time. It suggests low time-stability of jejunum strips model during long-term experiment. In contrast, the response of stomach (corpus and fundus) strips to ACh application did not change significantly during 6 h incubation. Moreover, the histological structure of the stomach preparations was maintained unaffected for a long incubation time. Thus, the isolated stomach strips can be described as an alternative experimental model of high time-stability during long-term experiments.

Haemolytic crisis in sheep as a result of chronic exposure to copper

Usually practicing veterinarians and animal keepers have to deal with inadequate supplementation of copper which causes deficiency diseases. However, instead of curing, the consequential intake of copper is likely to cause copper intoxication. Copper poisoning is observed particularly frequently, in sheep--the most sensitive domestic animal to copper toxicity. In most cases, sheep undergo chronic exposure to copper causing liver necrosis and resulting in massive haemolysis, haemoglobinuria and eventually in renal failure. The observed symptoms have an acute character and a set of them is called haemolytic crisis. The pathogenesis, signs and diagnosis of this syndrome are described in this article.