scholarly journals The Traditional Japanese Medicine Rikkunshito Promotes Gastric Emptying via the Antagonistic Action of the 5-HT3Receptor Pathway in Rats

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
K. Tominaga ◽  
T. Kido ◽  
M. Ochi ◽  
C. Sadakane ◽  
A. Mase ◽  
...  
Keyword(s):  
Gastric Emptying ◽  
Receptor Agonist ◽  
Delayed Gastric Emptying ◽  
Maximum Effect ◽  
Phenol Red ◽  
Dependent Manner ◽  
Antagonistic Action ◽  
Traditional Japanese Medicine ◽  
Male Wistar Rats ◽  
Dose Dependent

The traditional Japanese medicine rikkunshito ameliorates the nitric oxide-associated delay in gastric emptying. Whether rikkunshito affects gastric motility associated with 5-hydroxytryptamine (serotonin: 5-HT) receptors or dopamine receptors is unknown. We examined the effects of rikkunshito on the delay in gastric emptying induced by 5-HT or dopamine using the phenol red method in male Wistar rats. 5-HT (0.01–1.0 mg kg−1, i.p.) dose dependently delayed gastric emptying, similar to the effect of the 5-HT3receptor agonist 1-(3-chlorophenyl) biguanide (0.01–1.0 mg kg−1, i.p.). Dopamine also dose dependently delayed gastric emptying. The 5-HT3receptor antagonist ondansetron (0.04–4.0 mg kg−1) and rikkunshito (125–500 mg kg−1) significantly suppressed the delay in gastric emptying caused by 5-HT or 1-(3-chlorophenyl) biguanide. Hesperidin (the most active ingredient in rikkunshito) suppressed the 5-HT-induced delayed gastric emptying in a dose-dependent manner, the maximum effect of which was similar to that of ondansetron (0.4 mg kg−1). The improvement obtained by rikkunshito or ondansetron in delaying gastric emptying was completely blocked by pretreatment with atropine. Rikkunshito appears to improve delay in gastric emptying via the antagonistic action of the 5-HT3receptor pathway.

scholarly journals Urocortin 2 acts centrally to delay gastric emptying through sympathetic pathways while CRF and urocortin 1 inhibitory actions are vagal dependent in rats

2006 ◽  
Vol 290 (3) ◽  
pp. G511-G518 ◽  
Author(s):  
József Czimmer ◽  
Mulugeta Million ◽  
Yvette Taché
Keyword(s):  
Gastric Emptying ◽  
Receptor Agonist ◽  
Inhibitory Action ◽  
Delayed Gastric Emptying ◽  
Inhibitory Effect ◽  
Corticotropin Releasing Factor ◽  
Phenol Red ◽  
Sympathetic Blockade ◽  
Intracisternal Injection ◽  
Urocortin 1

We characterized the influence of the selective corticotropin-releasing factor 2 (CRF2) receptor agonist human urocortin 2 (Ucn 2), injected intracisternally, on gastric emptying and its mechanism of action compared with intracisternal CRF or urocortin (Ucn 1) in conscious rats. The methylcellulose phenol red solution was gavaged 20 min after peptide injection, and gastric emptying was measured 20 min later. The intracisternal injection of Ucn 2 (0.1 and 1 μg) and Ucn 1 (1 μg) decreased gastric emptying to 37.8 ± 6.9%, 23.1 ± 8.6%, and 21.6 ± 5.9%, respectively, compared with 58.4 ± 3.8% after intracisternal vehicle. At lower doses, Ucn 2 (0.03 μg) and Ucn 1 (0.1 μg) had no effect. The CRF2 antagonist astressin2-B (3 μg ic) antagonized intracisternal Ucn 2 (0.1 μg) and CRF (0.3 μg)-induced inhibition of gastric emptying. Vagotomy enhanced intracisternal Ucn 2 (0.1 or 1 μg)-induced inhibition of gastric emptying compared with sham-operated group, whereas it blocked intracisternal CRF (1 μg) inhibitory action (45.5 ± 8.4% vs. 9.7 ± 9.7%). Sympathetic blockade by bretylium prevented intracisternal and intracerebroventricular Ucn 2-induced delayed gastric emptying, whereas it did not influence intravenous Ucn 2-, intracisternal CRF-, and intracisternal Ucn 1-induced inhibition of gastric emptying. Prazosin abolished the intracisternal Ucn 2 inhibitory effect, whereas yohimbine and propranolol did not. None of the pretreatments modified basal gastric emptying. These data indicate that intracisternal Ucn 2 induced a central CRF2-mediated inhibition of gastric emptying involving sympathetic α1-adrenergic mechanisms independent from the vagus contrasting with the vagal-dependent inhibitory actions of CRF and Ucn 1.

Centrally administered neuropeptide Y delays gastric emptying via Y2receptors in rats

2001 ◽  
Vol 281 (5) ◽  
pp. R1522-R1530 ◽  
Author(s):  
Tadashi Ishiguchi ◽  
Taku Amano ◽  
Hiroaki Matsubayashi ◽  
Hitoshi Tada ◽  
Mikio Fujita ◽  
...  
Keyword(s):  
Gastric Emptying ◽  
Neuropeptide Y ◽  
Delayed Gastric Emptying ◽  
Low Frequency ◽  
High Amplitude ◽  
Receptor Subtypes ◽  
Dependent Manner ◽  
Intracerebroventricular Injection ◽  
Inhibitory Effects ◽  
Dose Dependent

It has been shown that centrally administered neuropeptide Y (NPY) delays gastric emptying. To determine the receptor subtypes of NPY mediating the inhibitory effects on gastric emptying, effects of intracerebroventricular injection of NPY, [Leu31,Pro34]NPY (a Y1agonist) and NPY-(3–36) (a Y2agonist) on solid gastric emptying and postprandial antropyloric motility were studied in conscious rats. Intracerebroventricular injection of NPY and NPY-(3–36), but not [Leu31,Pro34] NPY, delayed solid gastric emptying in a dose-dependent manner (0.03–3 nmol). After the feeding (40 min), contractions with low frequency and high amplitude of the antrum were frequently observed, and the peak contraction of the antrum occurred most often 3–6 s before the peak contraction of the pylorus. Intracerebroventricular injection of NPY and NPY-(3–36) (3 nmol), but not [Leu31,Pro34]NPY, significantly reduced antral contractions and the number of antropyloric coordination events. It is suggested that centrally administered NPY impairs postprandial antral contractions and antropyloric coordination via Y2receptors, resulting in delayed gastric emptying.

Action of the cholecystokinin antagonist L364,718 on gastric emptying in the rat

1988 ◽  
Vol 255 (5) ◽  
pp. G685-G689 ◽  
Author(s):  
T. Green ◽  
R. Dimaline ◽  
S. Peikin ◽  
G. J. Dockray
Keyword(s):  
Gastric Emptying ◽  
Physiological Role ◽  
Physiological Saline ◽  
Gastric Fistula ◽  
Phenol Red ◽  
Dependent Manner ◽  
Cholecystokinin Antagonist ◽  
Negative Feedback Control ◽  
Cck Receptor Antagonist ◽  
Dose Dependent

Cholecystokinin (CCK) is a potent inhibitor of gastric emptying. We have examined the effects of a novel potent peripheral CCK receptor antagonist (L364,718) on the action of endogenous and exogenous CCK octapeptide (CCK-8) on gastric emptying in the rat. In conscious gastric fistula rats, the recovery of liquid test meals of 3.0 ml (containing phenol red as a dilution marker) was determined over periods up to 8 min. Compared with saline, gastric emptying of solutions of peptone (4.5%), 50 mM HCl, and hyperosmolal saline was significantly delayed. The emptying of saline was also delayed by intravenous infusion of CCK-8 (400 pmol.kg-1.h-1). The CCK antagonist L364,718 reversed the effect of peptone in a dose-dependent manner and inhibited the response to exogenous CCK, but the emptying of physiological saline, 50 mM HCl, or hyperosmolal saline remained unchanged. A protease inhibitor (FOY-305) that is thought to release endogenous CCK by inhibiting negative feedback control by luminal proteases also delayed emptying, and this response was inhibited by L364,718. We conclude that CCK has a physiological role in the mediation of the effect of proteins on gastric emptying in the rat.

Modulation of Ca2+ transients in neonatal and adult rat cardiomyocytes by angiotensin II and endothelin-1

1996 ◽  
Vol 270 (3) ◽  
pp. H857-H868 ◽  
Author(s):  
R. M. Touyz ◽  
J. Fareh ◽  
G. Thibault ◽  
B. Tolloczko ◽  
R. Lariviere ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Receptor Agonist ◽  
Dependent Manner ◽  
Induced Responses ◽  
Ang Ii ◽  
Binding Studies ◽  
Vasoactive Peptides ◽  
Adult Cardiomyocytes ◽  
Etb Receptor ◽  
Dose Dependent

Vasoactive peptides may exert inotropic and chronotropic effects in cardiac muscle by modulating intracellular calcium. This study assesses effects of angiotensin II (ANG II) and endothelin-1 (ET-1) on intracellular free calcium concentration ([Ca2+]i) in cultured cardiomyocytes from neonatal and adult rats. [Ca2+]i was measured microphotometrically and by digital imaging using fura 2 methodology. Receptor subtypes through which these agonists induce responses were determined pharmacologically and by radioligand binding studies. ANG II and ET-1 increased neonatal atrial and ventricular cell [Ca2+]i transients in a dose-dependent manner. ANG II (10(-11) to 10(-7) M) failed to elicit [Ca2+]i responses in adult cardiomyocytes, whereas ET-1 increased [Ca2+]i in a dose-dependent manner. The ETA receptor antagonist BQ-123 significantly reduced (P 7< 0.05) ET-1 induced responses, and the ETB receptor agonist IRL-1620 (10(-7) to 10(-5) M) significantly increased (P < 0.05) [Ca2+]i in neonatal and adult cardiomyocytes. ET-1 binding studies demonstrated 85% displacement by BQ-123 and approximately 15% by the ETB receptor agonist sarafotoxin S6c, suggesting a predominance of ETA receptors. Competition binding studies for ANG II failed to demonstrate significant binding on adult ventricular myocytes, indicating the absence or presence of very few ANG II receptors. These data demonstrate that ANG II and ET-1 have stimulatory [Ca2+]i effects on neonatal cardiomyocytes, whereas in adult cardiomyocytes, ANG II-induced effects are insignificant, and only ET-1-induced responses, which are mediated predominantly via ETA receptors, are preserved. Cardiomyocyte responses to vasoactive peptides may thus vary with cardiac development.

scholarly journals The Effect of the mGlu8 Receptor Agonist, S-3,4-DCPG on Acquisition and Expression of Morphine-induced Conditioned Place Preference in Male rats

2021 ◽  
Author(s):  
Nazanin Kahvandi ◽  
Zahra Ebrahimi ◽  
Seyed Asaad Karimi ◽  
Siamak Shahidi ◽  
Iraj Salehi ◽  
...  
Keyword(s):  
Conditioned Place Preference ◽  
Metabotropic Glutamate Receptors ◽  
Preference Test ◽  
Place Preference ◽  
Male Rats ◽  
Dependent Manner ◽  
Metabotropic Glutamate ◽  
Male Wistar Rats ◽  
Dose Dependent

Abstract Background: The nucleus accumbens (NAc) plays a principal role in drug reward. It has been reported that metabotropic glutamate receptors (mGlu receptors) play a key role in the rewarding pathway(s). Previous studies have shown the vast allocation of the different types of mGlu receptors, including mGlu8 receptors, in regions that are associated with opioid rewards, such as the NAc. The aim of the present study was to evaluate the role of mGlu8 receptors within the NAc in the acquisition and expression phases of morphine induced conditioned place preference (CPP). Adult male Wistar rats were bilaterally implanted by two cannulas' in the NAc and were evaluated in a CPP paradigm. Selective mGlu8 receptor allosteric agonist (S-3,4-DCPG) was administered at doses of 0.03, 0.3, and 3 μg/0.5 μL saline per side into the NAc on both sides during the 3 days of morphine (5 mg/kg) conditioning (acquisition) phase, or before place preference test, or post-conditioning (expression) phase of morphine-induced CPP. Results: The results revealed that intra-accumbal administration of S-3,4-DCPG (0.3 and 3 μg) markedly decreased the acquisition in a dose-dependent manner but had no effect on expression of morphine-induced CPP. Conclusions: The findings suggest that activation of mGlu8 receptors in the NAc dose-dependently blocks the establishment of morphine-induced CPP and reduces the rewarding properties of morphine which may be related to the glutamate activity into the NAc and in reward pathway(s). These data suggest that mGlu8 receptor may be involved in conditioned morphine reward.

Inhibitory effect of ileal oleate on postprandial motility of the upper gut

1991 ◽  
Vol 261 (3) ◽  
pp. G458-G463 ◽  
Author(s):  
Z. Dreznik ◽  
D. Brocksmith ◽  
T. A. Meininger ◽  
N. J. Soper
Keyword(s):  
Oleic Acid ◽  
Gastric Emptying ◽  
Gamma Camera ◽  
Delayed Gastric Emptying ◽  
Early Period ◽  
Inhibitory Effect ◽  
Myoelectric Activity ◽  
Phenol Red ◽  
Mixed Meal ◽  
Postprandial Motility

To determine the effect of ileal oleate on postprandial gastrointestinal motility, duodenal and paired perfusion-aspiration ileal catheters and bipolar duodenal and jejunal electrodes were surgically implanted in five dogs. The ileum was perfused with either saline or an isotonic oleic acid emulsion at 2 ml/min. A 205-kcal mixed meal containing 120 ml liquid nutrient labeled with 111In-diethylenetriamine pentaacetic acid (DTPA) and solid food labeled with 99mTc was then administered orally. Gastric emptying was assessed by a gamma camera, myoelectric activity was continuously monitored, and duodenal-ileal transit of phenol red was determined over the ensuing 240 min. Ileal oleate reduced duodenal spikeburst frequency by 50% (P less than 0.05) and delayed gastric emptying of liquids and solids. Four hours after ingesting the meal, 62% of solids and 34% of liquids were retained in the stomach during oleic acid perfusion compared with 25 and 4%, respectively, when saline was perfused (P less than 0.05). Duodenal-ileal transit was markedly slowed by ileal perfusion with the oleic acid emulsion (P less than 0.001). Ileal oleate therefore exerted a profound inhibitory effect on proximal gut motility in the early period after ingestion of a mixed-nutrient meal in dogs.

Hyperpolarizing effect of aminophylline, theophylline, and cAMP on rat diaphragm fibers

1988 ◽  
Vol 64 (5) ◽  
pp. 1893-1899 ◽  
Author(s):  
O. Delbono ◽  
B. A. Kotsias
Keyword(s):  
Normal Values ◽  
Bath Temperature ◽  
Resting Membrane Potential ◽  
Maximum Effect ◽  
Dependent Manner ◽  
Rat Diaphragm ◽  
K Concentration ◽  
Dose Dependent ◽  
K Permeability

We studied the effect of aminophylline and theophylline (0.1–2 mM) on the resting membrane potential (Vm) of rat diaphragm fibers in vitro (25 degrees C). The main findings are the following. 1) Aminophylline and theophylline hyperpolarize the fibers in a dose-dependent manner. This effect is present with 0.1 and 0.25 mM of aminophylline and theophylline, respectively, and the maximum effect is reached with 1 mM of the drug (approximately 5–8 mV in comparison to the normal values). This effect is reversible by washing out the preparation with normal solution. 2) Dibutyryladenosine 3',5'-cyclic monophosphate (DBcAMP, 2 mM) produces a similar increment in the Vm. 3) The hyperpolarizing action observed in the presence of aminophylline, theophylline, and DBcAMP is suppressed by 5 X 10(-4) M ouabain or by lowering the bath temperature to 5 degrees C. These results suggest that the xanthines may directly or indirectly stimulate a Na-K pump. Two possibilities may be considered: 1) an electrogenic effect of the Na-K pump and 2) a reduction in the extracellular K+ concentration in the solution contacting the external side of the cell as a consequence of the activity of the Na-K pump. Alternative mechanisms such as a reduction in Na permeability or an increment in K permeability might collaborate in the hyperpolarizing effect of the drugs tested.

Effect of ethyl alcohol on motor function in canine stomach

1992 ◽  
Vol 262 (2) ◽  
pp. G223-G230
Author(s):  
L. C. Knight ◽  
A. H. Maurer ◽  
R. Wikander ◽  
B. Krevsky ◽  
L. S. Malmud ◽  
...  
Keyword(s):  
Gastric Emptying ◽  
Solid Food ◽  
Blood Levels ◽  
Lag Phase ◽  
Dependent Manner ◽  
Solid Meal ◽  
The Mean ◽  
High Doses ◽  
Mean Time ◽  
Dose Dependent

The aim of this study was to elucidate the effects of ethanol on gastric emptying and the trituration of solid food. With the use of a noninvasive physiological imaging technique, gastric processing of a radiolabeled solid meal was evaluated in unanesthetized dogs which ingested 6-8% ethanol solutions or received intravenous alcohol before the meal. Oral alcohol (resulting in blood levels up to 174 mg/dl) decreased the amplitude of antral contractions or completely abolished them. Alcohol did not significantly affect the fundamental frequency of contractions except at high doses, at which contractions were abolished. Alcohol lengthened the mean time to 50% of gastric emptying in a dose-dependent manner, from 132 +/- 3 min without alcohol to 160 +/- 10 min with oral alcohol at blood levels of 80-120 mg/dl (P less than 0.05). This was manifested by a lengthening of the lag phase, but there was no effect on the terminal slope of emptying (emptying rate) of the processed meal. At equal blood levels up to 120 mg/dl, orally administered alcohol had a more pronounced effect than intravenous alcohol. These data suggest that even low doses of dilute alcohol affect the ability of the antrum to process solid food and thereby contribute to impairment of gastric emptying.

scholarly journals Antinociceptive and Anti-edematous Activities of the Essential Oils of Two Balkan EndemicLaserpitium Species

2014 ◽  
Vol 9 (1) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Višnja Popović ◽  
Silvana Petrović ◽  
Maja Tomić ◽  
Radica Stepanović-Petrović ◽  
Ana Micov ◽  
...  
Keyword(s):  
Essential Oil ◽  
Essential Oils ◽  
Antinociceptive Effect ◽  
Dependent Manner ◽  
Paw Edema ◽  
Oral Gavage ◽  
Inflammatory Conditions ◽  
Pressure Test ◽  
Male Wistar Rats ◽  
Dose Dependent

In this paper antinociceptive and anti-edematous effects are examined of the essential oils of the underground parts of two Balkan endemic Laserpitium species (Apiaceae), L. zernyi and L. ochridanum. Furthermore, the essential oil of the underground parts of L. ochridanum is chemically characterised by GC and GC-MS. Antinociceptive and anti-edematous effects were measured in a rat model of localized inflammation, induced by carrageenan, using apparatus for the modified paw-pressure test, and plethysmometer, respectively. The effects of both Laserpitium essential oils were measured after oral gavage administration to male Wistar rats in doses of 25, 50 and 100 mg/kg. The main constituents of L. ochridanum essential oil were: α-pinene (33.2%), α-bisabolol (10.3%) and chamazulene (14.9%). The essential oil of L. zernyi was previously shown to be rich in α-pinene (31.6%) and α-bisabolol (30.9%). Both examined essential oils produced a significant dose-dependent antinociceptive effect. The corresponding ED50±SEM in producing antinociception were 45.9±4.9 mg/kg and 42.4±2.1 mg/kg for L. zernyi and L. ochridanum oil, respectively. Both essential oils also significantly reduced paw edema in a dose-dependent manner. The estimated ED50±SEM values for the anti-edematous effect were 36.3±4.5 mg/kg for L. zernyi oil and 45.1±11.3 mg/kg for L. ochridanum oil. These results suggest that the essential oils of both investigated Laserpitium species may be effective against pain and edema present in various inflammatory conditions.

Interaction between perchlorate and nifedipine on insulin secretion from mouse pancreastic islets

1993 ◽  
Vol 13 (2) ◽  
pp. 107-117 ◽  
Author(s):  
Gerd Larsson-Nyrén ◽  
Janove Sehlin
Keyword(s):  
Insulin Secretion ◽  
Insulin Release ◽  
Specific Effect ◽  
Maximum Effect ◽  
Dependent Manner ◽  
Inhibitory Effects ◽  
Maximum Inhibition ◽  
Second Phases ◽  
Dose Dependent ◽  
Higher Sensitivity

In order to elucidate the mechanisms responsible for the stimulatory effect of perchlorate (ClO4−) on insulin secretion, we have investigated the interaction between this chaotropic anion and the organic calcium antagonist nifedipine. This drug, known as a blocker of L-type calcium channels, was chosen as a tool to test the idea that ClO4− acts on insulin secretion by stimulating the gating of voltage-controlled Ca2+ channels. ClO4− amplified the stimulatory effect of D-glucose on insulin release from perfused pancreas (first and second phases) as well as from isolated islets incubated in static incubations for 60 min. This indicates that ClO4− amplifies physiologically regulated insulin secretion. Nifedipine reduced D-glucose-induced (20 mM) insulin release in a dose-dependent manner with half-maximum effect at about 0.8 μM and apparent maximum effect at 5 μM nifedipine. In the presence of 20 mM D-glucose, the inhibitory effects of 0.5, 1 or 5 μM nifedipine were only slightly, if at all, counteracted by perchlorate. When 12 mM ClO4− and 20 mM D-glucose were combined, calculation of the specific effect of ClO4− revealed that nifedipine produced almost maximum inhibition already at 0.05 μM. Thus, the perchlorate-induced amplification of D-glucose-stimulated insulin release shows higher sensitivity to nifedipine than the D-glucose-effect as such. This supports the hypothesis that perchlorate primarily affects the voltage-sensitive L-type calcium channel in the β-cell.

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