• The Korean Journal of Physiology
• /
• v.29 no.2
• /
• pp.233-241
• /
• 1995

The nonapeptide bradykinin has been shown to exhibit an array of biological activities including relaxation/contraction of various smooth muscles. In order to investigate the effects of bradykinin on the contractility and the electrical activity of antral circular muscle of guinea-pig stomach, the isometric contraction and membrane potential were recorded. Also, using standard patch clamp technique, the $Ca^{2+}-activated$ K currents were recorded to observe the change in cytosolic $Ca^{2+}$ concentration. $0.4 {\mu}M$ bradykinin induced a triphasic contractile response (transient contraction-transient relaxation-sustained contraction) and this response was unaffected by pretreatment with neural blockers (tetrodotoxin, atropine and guanethidine) or with apamin. Bradykinin induced hyperpolarization of resting membrane potential and enhanced the amplitude of slow waves and spike potentials. The enhancement of spike potentials was blocked by neural blockers. Both the bradykinin-induced contractions and changes in membrane potential were reversed by the selective $B_2$-receptor antagonist $(N{\alpha}-adamantaneacetyl-_{D}-Arg-[Hyp, Thy,_{D}-Phe]-bradykinin)$. In whole-cell patch clamp experiment, we held the membrane potential at -20 mV and spontaneous and transient changes of Ca-activated K currents were recorded. Bradykinin induced a large transient outward current, consistent with a calcium-releasing action of bradykinin front the intracellular calcium pool, because such change was blocked by pretreatment with caffeine. Bradykinin-induced contraction was also blocked by pretreatment with caffeine. From these results, it is suggested that bradykinin induces a calciumrelease and contraction through the $B_{2}$ receptor of guinea-pig gastric smooth muscle. Enhancement of slow wave activity is an indirect action of bradykinin through enteric nerve cells embedded in muscle strip.

• The Journal of Internal Korean Medicine
• /
• v.21 no.1
• /
• pp.87-99
• /
• 2000

Objectives : This is the experimetal paper to evaluate and compare the effects of Bosimgunbitang(補心健脾湯) with those of Jungjungamiyijintang(正傳加味二陳湯) on contraction of isolated organs, anti-ulcer, secretion of gastric juice, secretion of gastrin in serum, transport ability of intestine, analgesic effect and sedative effect Methods : We used mice and rats administered with the extract of the above herbs. Results: Bosimgunbitang and jungjungamiijintang showed the inhibitory effect on the smooth muscle contraction of the isolated ileum induced by acethylcholine chloride and barium chloride in mice. transport ability of intestine. Bosimgunbitang and jungjungamiijintang showed the inhibitory effect on the contraction of the fundus-strip induced by acethylcholine chloride and barium chloride in rats. The preventive effect on pyloric ulcer, indomethacin induced ulcer and ethanol-HCl induced ulcer bf mice was significant. The inhibitory effect of Bosimgunbitang on gastric free acidity, total acidity in Shay rats was significant. The inhibitory effect of on gastrin secretion in serum was significant after only 1 hour when the Bosimgunbitang and jungjungamiijintang was administered. The promoting effect of the jungjungamiijintang on the transport ability of small intestine was significant in the high concentration. The promoting effect of the Bosimgunbitang and jungjungamiijintang on the transport ability of large intestine was significant. The analgesic and the sedative effect were recognized. It meaned that Bosimgunbitang and jungjungamiijintang effected on the C.N.S.. Conclusion : Bosimgunbitang and jungjungamiijintang have the inhibitory effect on the smooth muscle abnormal contraction of the isolated ileum and the anti-ulcer effect to prevent, secretion of gastric juice and gastrin in serum. And they also have to increase a transport ability of intestine, analgesic effect and sedative effect. Jungjungamiijintang especially is eminent for analgesic effect while Bosimgunbitang has excellent sedative effect.

• Journal of Yeungnam Medical Science
• /
• v.16 no.2
• /
• pp.318-325
• /
• 1999

Background: Anticholinesterase drug inhibits acetylcholinesterase(AChE), induce accumulation of acetylcholine(ACh) near cholinergic receptors and cholinergic stimulation. This experiment was performed to study the effects of anticholinesterase drugs on gastric motility and the effect of ethanol on anticholinesterase drug-induced motility change. Materials and Methods: After excision of stomach, $2{\times}10mm$ circular muscle strips were made, which were then fixed to the isolated muscle chamber. An isometric tension transducer was used to measure the contraction change of the gastric smooth muscle strips after drug addition. Results: Fenthion, an irreversible anticholinesterase drug, increased ACh induced contraction of gastric smooth muscle strips and PAM, a cholinesterase activator, antagonized this action. Physostigmine, a reversible anticholinesterase drug, also increased the ACh induced contraction. The gastric motility was decreased by PAM. Ethanol, which is known to induce smooth muscle relaxation, inhibited the increase of contraction by fenthion. Conclusion: These results indicate that irreversible and reversible anticholinesterase drugs increase gastric motility and antagonized by cholinesterase activating drugs. And when exposed to both ethanol and anticholinesterase drug, gastric motility was decreased by the smooth muscle relaxation effect by ethanol.

• The Korean Journal of Physiology and Pharmacology
• /
• v.4 no.5
• /
• pp.369-378
• /
• 2000

This study was undertaken to investigate an involvement of nitroxergic innervation in gastric smooth muscle of rat. Isometric tension study, the measurement of single cell length, NADPH diaphorase stain of smooth muscle layers and neuronal nitric oxide synthase (nNOS) western blotting were performed. Sodium nitroprusside (SNP), a nitric oxide donor, relaxed the muscle strips precontracted by acetylcholine (ACh) in a concentration-dependent manner. Pretreatment of L-arginine decreased the contraction induced by electric field stimulation (EFS). Pretreatment of $N^G-nitro-L-arginine$ methyl ester (L-NAME), a NOS inhibitor, increased the EFS-induced contractions. LY 83583, a guanylate cyclase (GC) inhibitor, reversed the inhibitory actions of L-arginine on the muscle contractions. The effects of L-Arginine, L-NAME and LY 83583 on ACh-induced contractions were not significant. L-arginine reduced the EFS-induced contraction in circular muscle, whereas L-NAME enhanced the EFS-induced contraction in longitudinal strips. By EFS, the phasic contractions appeared approximately $20{\sim}25$ seconds later. L-NAME significantly shortened the delay time to about $2{\sim}3$ seconds. In single cell study, ACh contracted gastric smooth muscle cells, SNP relaxed the cells, and the latter also inhibited the ACh-induced contraction. LY 83583 enhanced the ACh-induced contraction and antagonized SNP-induced relaxation. NADPH diaphorase activity was assessed by a histochemistry, nitroblue tetrazolium (NTB) staining. Positive staining was observed in both circular and longitudinal muscle layers. L-arginine increased the staining, while L-NAME decreased the staining. Western blotting for nNOS proved the presence of nNOS in rat gastric smooth muscle. EFS and additional $Ca^{2+}$ increased nNOS protein expression. These results suggest that in rat stomach, both circular and longitudinal muscle layers are innervated with nitroxergic nerves which relax the gastric smooth muscle via NO-cGMP pathway.

• The Korean Journal of Physiology
• /
• v.25 no.2
• /
• pp.133-146
• /
• 1991

In order to elucidate systematically the effects of serotonin on gastric motility of guinea-pig, the contractile and electrical responses to serotonin were recorded using four kinds of muscle strips prepared from antral circular, antral longitudinal, fundic circular, and fundic longitudinal muscles. Experiments were performed using various methods including isometric contraction recording, transmural electrical field stimulation, junction potential recording, intracellular microelectrode technique, and partition stimulation method. The results were as follows: 1) The effect of serotonin on spontaneous contractions was inhibitory in the circular muscle strips of the antrum and fundus, while it was excitatory in the longitudinal muscle strips of the antrum and fundus. Serotonin changed mainly phasic contractions of both the circular and longitudinal muscle strips in the antrum, while it changed mainly tonic contractions of both the circular and longitudinal muscle strips in the fundus. 2) On the contractions induced by transmural nerve stimulation, serotonin decreased the amplitude in the circular muscle strips of the antrum, but it increased them in the other three groups of muscle strips(antral longitudinal, fundic circular, and fundic longitudinal). 3) On the contractions induced by direct muscle stimulation, serotonin decreased the amplitude in the circular muscle strips of the antrum and fundus. 4) In the fundic circular muscle strips serotonin potentiated excitatory junction potentials (EJPs), and in the antral circular muscle strips it evoked EJPs after inhibitory junction potentials(IJPS). 5) In the antral circular muscle strips serotonin did not affect the slow wave even at the disappearance of spontaneous contractions. On the contrary it increased the amplitude of the slow wave, when the spike component was potentiated and the second component was inhibited. 6) In the antral circular muscle strips the membrane potential was slightly hyperpolarized, but the membrane resistance was not changed. From the above results following conclusions could be made. 1) Serotonin inhibits spontaneous contractions of the circular muscle layer and it increases those of the longitudinal one, irrespective of the gastric region. 2) In the guinea-pig stomach there exists a serotoninergic facilitatory neuromodulation system which exerts its effect on cholinergically mediated contraction. 3) The excitation-contraction decoupling was observed in the effect of serotonin.

• The Journal of Internal Korean Medicine
• /
• v.31 no.2
• /
• pp.212-223
• /
• 2010

Objectives : The aims of this study were to evaluate whether gastric contractility could be measured by bowel sound of rats, and whether gastrointestinal side effect of any herbal restoratives would be related with their inhibition of gastric contraction. Methods : Streptozotocin (STZ)-induced diabetic rats were used as a gastric hypocontraction model. At the time of 6 weeks after induction of diabetes, 2mL of normal saline (NS) and 2mL of extract solution each containing 125mg/kg of Bojoongikki-tang (BJ), Sipjeondaebo-tang (SJ), Youngkaechulgam-tang (YG) were given to Normal (NR) and diabetic rats (DR), respectively. Bowel sound was recorded for 30 minute in fasting, and 120 minute of their administration. Gastric motility index was serially calculated with the ratio of accumulated potentials of post-administration/fasting state every 10 minutes. Results : Gastric contractility between NR and DR could be significantly distinguished by bowel sound auscultation. BJ had a decreasing effect, SJ had a bidirectional effect, and YG had an increasing effect on gastric contractility measured by bowel sound auscultation. Conclusions : BJ showed the possibility of inhibitory effects on gastric contraction. So, before administration, a gastric motility test should be recommended to prevent possible side effects in patients with gastric hypocontractility.

• The Korean Journal of Physiology and Pharmacology
• /
• v.3 no.3
• /
• pp.275-282
• /
• 1999

Muscle strips and muscle cells from cat stomach were used to investigate whether spontaneously formed cyclic nucleotides were involved in the inhibition of gastric smooth muscle contraction. A phosphodiesterase inhibitor, 3-isobutyl-1-methylxanthine (IBMX), increased the levels of both cyclic GMP (cGMP) and cyclic AMP (cAMP) in resting state cells, while decreasing acetylcholine-induced muscle contraction. Under the influence of IBMX, SQ22536, an adenylyl cyclase inhibitor and methylene blue, a guanylyl cyclase inhibitor completely blocked increases in cAMP and cGMP respectively, without any effect on contraction. However, the combination of SQ22536 and methylene blue completely blocked increases in both cAMP and cGMP levels and stimulated contractions markedly even in the presence of IBMX. Muscle contraction inhibitors such as isoprenaline, vasoactive intestinal polypeptide and sodium nitroprusside also appeared to increase cyclic nucleotide levels which decreased contraction. Which nucleotide increased the most was dependent on the agonist used. Therefore, irrespective of the cyclic nucleotide class, the spontaneous formation of cyclic nucleotides should be considered in evaluating the mechanism of gastric smooth muscle relaxation.

• Korean Journal of Pharmacognosy
• /
• v.15 no.3
• /
• pp.128-133
• /
• 1984

The extracts of Yukgunja-tang which has been used in some of gastroin testinal disorders were examined for secretion of gastric juice and movement of isolated stomach of rabbit. Experiments were performed with the dried extract of Yukgunja-tang (sample I) and the dried extract compound made of each drug of Yukgunja-tang (sample II). The secretion of gastric juice at the doses of 25.0 and 50.0mg/kg p.o. of sample I showed the decreases of 34.3 and 43.3%, respectively, as compared with control group, whereas the secretion at a dose of 76.8g/kg of sample II showed 43.1%. In gastric acid secretion, sample I showed 50.0% decrease at a dose of 50.0mg/kg and sample II showed 46.2% decrease at a dose of 76.8mg/kg. In pepsin output sample I showed 17.8 and 23.4% decreases at a dose of 25.0 and 50.0mg/kg, respectively, whereas sample II showed 22.5% decrease at a dose of 76.8mg/kg. The isolated stomach of rabbit showed dose-responsive contraction by addition of sample I, however the contraction was not observed by sample II.

• Journal of Veterinary Clinics
• /
• v.26 no.6
• /
• pp.574-577
• /
• 2009

The purpose of this study is to evaluate gastric motility of conscious minipigs with ultrasonography from contraction number of the pyloric antrum and gastric emptying time (GET). Five-month-old, clinically healthy minipigs weighing 13.5-15 kg were used for this experiment. Assessment of gastric motility was performed using saline (10 ml/kg) in all five minipigs. Contraction number of the pyloric antrum for 3 minutes and gastric emptying time were calculated. Gastric emptying time was considered to be the time at which the antral area returned to the basal value. The mean value of contraction number of the pyloric antrum before feeding was 1.60${\pm}$2.30 (mean${\pm}$SD) for 3 min and the overall mean value after saline administration was 5.40${\pm}$3.62 for 3 min. The mean value of GET by area was 58.06${\pm}$5.23 min. This data can be used as basic database for evaluation of gastric motility in minipigs as normal and various experimental models.

• Journal of Sasang Constitutional Medicine
• /
• v.9 no.2
• /
• pp.187-201
• /
• 1997

An experimental study was done to examine the effects of Dokwhaljiwhang-tang on gastro-intestinal track and central nervous system and were undertaken by being carried out with rat. The following results have been obtained ; 1. Dokwhaljiwhang-tang showed to have an inhibitory effect on the smooth muscle contraction of the isolated ileum by acetylcholene chloride and barium chloride. 2. Dokwhaljiwhang-tang showed to have an inhibitory effect on the contraction of the gastric fundus-strip by acetylcholine chloride and barium chloride. 3. The preventive effect was recognized on the pylorus-ligated ulcer, by administration of Dokwhaljiwhang-tang. 4. The preventive effect was not recognized on the indomethacine -induced ulcer, by administration of Dokwhaljiwhang-tang. 5. The inhibitory effects on the secretion gastric juice, free acidity were recognized, by administration of Dokwhaljiwhang-tang 6. The transport ability in the small intestine was increased, by administration of Dokwhaljiwhang-tang. 7. The transport ability in the large intestine was increased, by administration of Dokwhaljiwhang-tang. 8. The analgesic effect was recognized, by administration of Dokwhaljiwhang-tang. 9. The effect of sleeping time was not recognized, by administration of Dokwhaljiwhang-tang. according to the results, it is considered that Dokwhaljiwhang-tang has effects of gastric ulcer, chronic gastritis,hyper-acidity, gastroptosis such as abdominal discomfort, gastric acid, indigestion and anorexia.