• The Korean Journal of Physiology and Pharmacology
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• v.22 no.5
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• pp.539-546
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• 2018

Botulinum toxin type A (BoNT/A) has been used therapeutically for various conditions including dystonia, cerebral palsy, wrinkle, hyperhidrosis and pain control. The substantia gelatinosa (SG) neurons of the trigeminal subnucleus caudalis (Vc) receive orofacial nociceptive information from primary afferents and transmit the information to higher brain center. Although many studies have shown the analgesic effects of BoNT/A, the effects of BoNT/A at the central nervous system and the action mechanism are not well understood. Therefore, the effects of BoNT/A on the spontaneous postsynaptic currents (sPSCs) in the SG neurons were investigated. In whole cell voltage clamp mode, the frequency of sPSCs was increased in 18 (37.5%) neurons, decreased in 5 (10.4%) neurons and not affected in 25 (52.1%) of 48 neurons tested by BoNT/A (3 nM). Similar proportions of frequency variation of sPSCs were observed in 1 and 10 nM BoNT/A and no significant differences were observed in the relative mean frequencies of sPSCs among 1-10 nM BoNT/A. BoNT/A-induced frequency increase of sPSCs was not affected by pretreated tetrodotoxin ($0.5{\mu}M$). In addition, the frequency of sIPSCs in the presence of CNQX ($10{\mu}M$) and AP5 ($20{\mu}M$) was increased in 10 (53%) neurons, decreased in 1 (5%) neuron and not affected in 8 (42%) of 19 neurons tested by BoNT/A (3 nM). These results demonstrate that BoNT/A increases the frequency of sIPSCs on SG neurons of the Vc at least partly and can provide an evidence for rapid action of BoNT/A at the central nervous system.

• Korean Journal of Veterinary Research
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• v.46 no.4
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• pp.323-326
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• 2006

Suaeda (S.) asparagoides $M_{IQ}$, one of the halophyte groups, has been used as a folk remedy for digestive disturbances in Korea. However, its pharmacological activity on gastrointestinal motility has not been reported yet. In this study, the effects of this halophyte extracts with various solvent fractions (ethanol, hexane, chloroform, ethyl acetate, butanol, and water) on mice ileal spontaneous motility was examined. All solvent fractions at the concentration of $100{\mu}g/ml$ showed inhibitory actions on spontaneous motility of ileum with the potency order of water > 70% ethanol > hexane ${\gg}$ chloroform ${\geq}$ butanol ${\geq}$ ethyl acetate, respectively. In addition, the water fraction of extracts from S. asparagoides $M_{IQ}$ (WFSA) dose-dependently ($1-100{\mu}g/ml$) inhibited the amplitude of spontaneous phasic contraction and area under the contractile curve (AUC). The inhibitory effect of water fraction at the concentration of $10{\mu}g/ml$ was not affected by tetrodotoxin (TTX), $Na^+$ channel blocker ($1{\mu}M$), and $N^w$-nitro-L-arginine Methyl Ester (L-NAME), nitric oxide synthase inhibitor ($100{\mu}M$). However, cyclopiazonic acid (CPA, $10{\mu}M$), inhibitor of sarcoplasmic reticulum $Ca^{2+}$-ATPase, almost blocked the inhibitory effects of WFSA ($10{\mu}g/ml$) on the spontaneous phasic contraction of mouse ileum. But, CPA did not inhibit the lowering basal tone effects of WFSA. The result of this study showed that various extracts of S. asparagoides $M_{IQ}$ induce inhibitory effects on spontaneous contraction of mice ileal segments. More over, the polar solvent fractions were shown to be more potent than non-polar solvent fractions. The effects of S. asparagoides $M_{IQ}$ extracts are not mediated by nerve or nitric oxide. The inhibitory effects of WFSA at least partially mediated by sarcoplasmic reticulum $Ca^{2+}$-ATPase. However, further study is required to determine the exact pharmacological mechanisms of this halophyte on its gastrointestinal motility inhibitory effects.

• The Korea Journal of Herbology
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• v.26 no.4
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• pp.75-81
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• 2011

Objectives : Magnoliae officinalis Cortex (MOC) has been used in traditional medicine for digestive diseases in Korea, China and Japan. However, Machili thunbergii Cortex (MTC) also has been used as a substitute of MOC in Korea sometimes. Thus, this study was carried out to investigate and compare the effects of MOC and MTC on intestinal motility of isolated small intestinal segments from ICR mouse. Methods : Changes in motility were recorded via isometric transducers connected to a data acquisition system and amplitude, frequency and area under the curve (AUC) of intestinal spontaneous phasic contraction were compared. Results : The MOC extracts ($1{\sim}{\mu}g/mL$) dose-dependently decreased both amplitudes and frequencies of the spontaneous phasic contraction, but not AUC. However, high concentration of MOC (100 ${\mu}g$/mL) evoked tonic contraction. And it was not inhibited by tetrodotoxin, a sodium channel blocker, and nifedipine, a L-type $Ca^{2+}$ channel antagonist. These results suggested that MOC (100 ${\mu}g$/mL)-induced tonic contraction is not mediated by nerve or L-type $Ca^{2+}$ channel. On the other hand, the MTC extracts dose-dependently inhibited amplitude and AUC, but not the frequency. Conclusions : Although both MOC and MTC affected intestinal motility, MOC is more effective on intestinal motility than MTC. And MOC has been used as a traditional medicine for a long time but not MTC. Thus, we suggested that MTC should not be used in Korea as a substitute of MOC and MOC might be useful traditional medicine for gastrointestinal disease. The mechanism of MOC is still remained to elucidate.

• Korean Journal of Veterinary Research
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• v.37 no.1
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• pp.119-128
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• 1997

The relaxation of gastric fundus smooth muscles is the primary physiological event which induces the receptive relaxation of monogastric animals. L-arginine/Nitric oxide(L-arg/NO) system is known to mediate the inhibitory non-adrenergic non-cholinergic(NANC) neurotransmission in various tissues including gastrointestinal smooth muscles. The longitudinal smooth muscles of porcine gastric fundus showed fast relaxation during electrical field stimulation(EFS) and rebound contraction after EFS in NANC condition. So, the purpose of present study was elucidation of the neurotrasmitters related to the NANC relaxation and explanation of the relation between NANC relaxation and L-arg/NO system. The longitdinal smooth muscles of porcine gastric fundus were hung in the organ bath and under the presence of guanethidine($5{\times}10^{-5}M$), precontraction was induced by carbachol($1{\times}10^{-6}M$). The muscle responses to EFS and drugs were isomerically recorded. The rusults were summarized as follows. 1. The longtudinal muscles of porcine gastric fundus showed frequency-dependent relaxation and rebound contraction to electrical field stimulaton(1ms, 8V, 1~16Hz, 20sec, EFS). These responses were blocked by tetrodotoxin($1{\times}10^{-6}M$). 2. The relaxation and rebound contraction of the longitudinal muscles of porcine gastric fundus to EFS were inhibited by L-NAME($2{\times}10^{-5}M$). The inhibitory effect of L-NAME was antagonized by L-arginine($1{\times}10^{-3}M$), but not by D-arginine($1{\times}10^{-3}M$). 3. Exogenous NO($NaNO_2$, $1{\times}10^{-5}{\sim}1{\times}10^{-4}M$, pH=2.0) caused concentration-dependent relaxation as EFS did. 4. Methylene Blue($2{\times}10^{-5}M$), a soluble guanylate cyclase inhibitor, inhibited the relaxation and rebound contraction of the longitudinal muscles of porcine gastric fundus induced by EFS, but N-ethlmaleimide, a adenylate cyclase inhibitor, did not. 5. 8-Br-cGMP($1{\times}10^{-6}{\sim}3{\times}10^{-6}M$), permeable cGMP analogue, induced dose-dependent relaxation. but 8-Br-cAMP($1{\times}10^{-6}{\sim}3{\times}10^{-6}M$), permeable cAMP analogue, did not. Both did not evoked rebound contraction. 6. ${\alpha}$-chymotrypsin did not affect the relaxation of the longitudinal muscles of porcine gastric fundus. 7. Reactive blue 2($1{\times}10^{-4}M$, 40min) siginificantly inhibited the rebound contraction induced by EFS and inhibited contraction caused by exogenous ATP($1{\times}10^{-4}{\sim}1{\times}10^{-3}M$). These results suggests that NANC relaxation of the longitudinal muscles of porcine gastric fundus mainly mediated by NO and the rebound contraction is related to NO and other neurotransmitters.

• Korean Journal of Veterinary Research
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• v.35 no.3
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• pp.459-469
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• 1995

As S-nitrosothiols were proposed as nitrergic carriers in vascular and nonvascular smooth muscle, we have investigated the relaxant properties of several S-nitrosothiols in the porcine retractor penis(PRP) muscle and compared them with the effects of exogenously added NO, electrical field stimulation(EFS) of NANC nerves and sodium nitroprusside(SNP). Also the influences of oxyhemoglobin and hydroquinone on the relaxant responses were investigated. In addition, effects of NO on membrane potentials and its involvement in the generation of inhibitory junction potential(IJP) were investigated with conventional intracellular microelectrode technique. The results were summerized as follows. 1. Frequency-dependent relaxations of PRP muscle were induced by EFS to NANC nerve. Tetrodotoxin($1{\times}10^{-6}M$) abolished the relaxations of PRP muscle induced by EFS, and L-NAME(($2{\times}10^{-5}M$) and methylene blue($4{\times}10^{-5}M$) inhibited the relaxations. L-NAME-induced inhibition of the relaxations was reversed by L-arginine($1{\times}10^{-3}M$), but not by D-arginine. 2. Exogenous NO($1{\times}10^{-5}-1{\times}10^{-4}M$), sodium nitroprusside(($1{\times}10^{-7}-1{\times}10^{-4}M$) induced dose-dependent relaxations of PRP muscle. All S-nitrosothiols($1{\times}10^{-7}-1{\times}10^{-4}M$) tested relaxed the PRP muscle in dose-dependent manner and the potency order was SNAP>GSNO>CysNO>SNAC. 3. Oxyhemoglobin($5{\times}10^{-5}M$) blocked the relaxation induced by exogenous NO and inhibited EFS-, S-nitrosothiols-, and SNP-induced relaxation. 4. Hydroquinone($1{\times}10^{-4}M$) also abolished the relaxations induced by exogenous NO, and reduced the relaxations induced by S-nitrosothiols, but did not affect EFS- and SNP-induced relaxations. 5. SNP($2{\times}10^{-6}-5{\times}10^{-6}M$) relaxed muscle strips but the membrane potentials were not affected. 6. EFS with several pulses(1ms, 2Hz, 80V) produced an inhibitory junction potential(IJP) with muscle relaxation. They were abolished by TTX($2{\times}10^{-6}M$). $N^G$-nitro-$_{\small{L}}$-arginine(L-NNA, $2{\times}10^{-5}M$) abolished the muscle relaxation, but had no effect on IJP.

• The Korean Journal of Pharmacology
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• v.31 no.1 s.57
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• pp.39-51
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• 1995

The roles of ${\beta}-adrenoceptor$ were well known in hyperthyroidal heart, but not with ${\alpha}-adrenoceptor$. So we studied the effects of phenylephrine on membrane potential, intracellular sodium activity ($a^{i}_{Na}$), twitch force, and intracellular pH ($pH_i$) by continuous intracellular recordings with ion-selective and conventional microelectrodes in the papillary muscles of hyperthyroid guinea pig heart. ${\alpha}_1-adrenoceptor$ stimulation by phenylephrine (10^{-5}\;or\;3{\times}10^{-5}M$) produced the following changes: variable changes in action potential duration, a hyperpolarization ($1.5{\pm}0.1mM$) of the diastolic membrane potential, an increase in $a^{i}_{Na}\;(0.4{\pm}0.15mM)$, a stronger positive inotropic effect ($220{\pm}15%$), an increase in $pH_i\;(0.06{\pm}0.002\;unit)$. These changes were flocked by prazosin and atenolol. This indicated that the changes in membrane potential, $a^{i}_{Na}$ twitch force, and $pH_i$ are mediated by a stimulation of the ${\alpha}_1-adrenoceptor$. Ethylisopropylamiloride ($10^{-5}$) also blocked the increase in $a^{i}_{Na}$ and twitch force. On the other hand, strophanthidin, tetrodotoxin, $Cs^+$ or verapamil did not block the increase in $a^{i}_{Na}$ and twitch force. Thus, it was suggested that ${\alpha}_1-adrenoceptor$ stimulation increased $a^{i}_{Na}\;and\;pH_i$ by stimulation of $Na^{+}-H^{+}$ exchange, thereby allowing intracellular alkalinization and $a^{i}_{Na}$ increase. These results were very different from euthyroidal heart which showed ${\alpha}_1-adrenoceptor$-induced decrease in $a^{i}_{Na}$ and initial negative inotropic effect. From the above results, it was concluded that ${\alpha}_1-adrenoceptor$ had a important role in hyperthy-roidal heart.

• Journal of Veterinary Clinics
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• v.6 no.2
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• pp.227-259
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• 1989

Waterpepper is a weed which grows on damp soil. especially near swamps, and in shallow water of ponds and ditches. It Is widespread throughout the country In abundant colonies. In the present experiments, possible toxic effects of waterpepper were investigated in ruminants. Pour cows were fed waterpepper ad libitum or by force in the from of green forage, hay and/or powder, 8 goats were administered in the form of methanol extract, and 4 goats, crude juice, into the lumen. Clinical signs were examined as well as urinalysis, hematology, serum chemical analysis, pH/blood gas analysis and chclinesterase activities following administration of waterpepper. Six goats which were administered the methanol extract or crude juice were sacrificed for pathological examinations., In addition to the clini copathological examinations, the chemical constituents of waterpepper were qualitively analyzed from the methanol extract and the Effects of the waterpepper crude juice were examined on the motility of rabbit duodenum and uterus. It is revealed that waterpepper contains steroids, terpenoids, flavonoids, tannin and essential oils in the methanol extract and nitrates in the crude juice. The crude juice of waterpepper relaxed the rabbit uterine and duodenal smooth muscles. The constraction of duodenum by acetylcholine or BaCl$_2$ were partially inhibited by pretreatment of the crude juice. However, the relaxation of duodenum by the crude juice was not blocked by the pretreatments of phenoxybenzamlne, propranolol, cocaine, reserpine and tetrodotoxin. The constituents of waterpepper to evoke elaxation of duodenal smooth muscle were stable to heat. The cows administered waterpepper showed common clinical symptoms such as acrid expression, restlessness, dullness, inappetence, anorexia, severe diarrhea, mild bloat and left displacement of abomasum, while bloody feces was shown in a cow. The goats administered the mothanol extract showed common clinical signs such as acrid expression, restlessness, dullness, inappetence and soft feces, while bloody feces was shown in a goat, A goat adminstered the crude juice showde bloody feces and diarrhea. Respiratory rates and heart beats were increased along with diarrhea in the experimental cows. The erythrocyte counts and MCHC were decreased whereas PCV, MCV and neutrophils were increased in the cows administered waterpepper. In goats administered methanol extract, there were decreases in erythrocytes, PCV and hemoglobin content, and an increase in MCHC. The goats ingester with the crude juice showed negligible changes in hematologic values compared with control group which was administered the same amount of water instead of the crude juice. The contents of serum calcium, Inorganic phosphorus, magnesium, Iron, glucose, cholesterol, total protein, triglycerides and phospholipids were tended to decrease in cows. In goats serum iron, glucose, triglycerides, cholesterol, BUN and phospholipids content were decreased while the content of sodium and chloride were increased after administration of the methamol extract The goats ingested with the crude juice did not show significant changes in serum chemical analysis. Even though there were some pathological findings such as hyperemia in the small intestines and kidneys and swelling of liver parenchymal cells, the values of serum AST, ALT, LDH, alkaline phosphatase, total bilirubin and creatinine did not change significantly. While proteins, hemoglobin and blood were detected in the urine of cows, urine pH, ketone bodies, glucose, bilirubin and urobilinogen content were normal or undetected. There were no significant changes in pH/bolld gas analysis data of cows and cholinesterase activities of plasma and erythrocytes of cows and goats ingested with waterpepper or the methanol extract. It is concluded that waterpepper irritates the gatrointestinal system, causes abdominal pain, relaxes the gastrointestinal smooth muscle and dilatates blood vessels supplied to the system. The irritation and relaxation may lead to abnormal fermentation, maldigestion and malabsorption of nutrients and result in diarrhea, body feces, mild bloat and left displacement of abomasum.

• The Korean Journal of Pharmacology
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• v.32 no.3
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• pp.301-309
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• 1996

Since it has been reported that the depolarization-induced NE release is inhibited by activation of presynaptic $A_1-adenosine$ heteroreceptor in hippocampus, a large body of experimental data on the post-receptor mechanism of this process has been accumulated. But, the post-receptor mechanism of presynaptic $A_1-adenosine$ receptor on the NE release has not been clearly elucidated yet. Therefore, it was attempted to clarify the participation of $K^+-channel$ in the post-receptor mechanisms of the $A_1-adenosine$ receptor-mediated control of NE release in this study. Slices from rat hippocampus were equilibrated with $^3H-norepinephrine$ and the release of the labelled products was evoked by electrical stimulation (3 Hz, 5 $VCm^{-1}$, 2 ms, rectangular pulses), and the influence of various agents on the evoked tritium-outflow was investigated. Adenosine, in concentrations ranging from $1{\sim}30\;{\mu}M$, decreased the NE release in a dose-dependent manner, without affecting the basal rate of release. 4AP $(1{\sim}30{\mu}M)$, a specific A-type $K^+-channel$ blocker, increased the evoked NE release in a dose-related fashion, and the basal rate of release is increased by 10 and $30{\mu}M$. TEA $(1{\sim}10{\mu}\;M)$, a nonspecific $K^+-channel$ blocker, increased the evoked NE release in a dose-dependent manner without affecting basal release. The adenosine effects were significantly inhibites by 3 ${\mu}M$ 4AP and 10 mM TEA treatment. 4AP $(30{\mu}M)-$ and TEA (10 mM)-induced increments of evoked NE release were completely abolished in $Ca^{++} free, but these were recoverd in low $Ca^{++} medium. And the effects of $K^+-channel$ blockers in low $Ca^{++} medium were inhibites and abolishes by $Mg^{++} (4 mM) adding and TTX $(0.3{\mu}M)$ adding medium, respectively. These results suggest that the decrement of the evoked NE-release by $A_1-adenosine$ receptor is mediated by 4AP and TEA sensitive $K^+-channel$.

• The Korean Journal of Pharmacology
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• v.16 no.1 s.26
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• pp.25-34
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• 1980

The in vitro guinea pig ureter responded to 5 sec trains of electrical stimuli with two contractions; the first an 'on response' (ON) occurred with $0.1{\sim}0.3$ sec after the onset o the stimulus train, the second an 'off response'(OFF) occurred $0.2{\sim}1.0$ sec after the termination of the stimulus train. Relaxation occurred between the two responses during a time when the stimulus was still being delivered. Longer duration and/or higher frequencies of stimuli within the train were required to elicit the OFF than the ON. Decreasing temperature from $37^{\circ}$ to $22^{\circ}$ decreased ON amplitude and increased OFF amplitude. $Ca^{++}$-free solution, 2 mM EDTA, 1 mM $Mn^{++}$ or $1{\mu}M$ verapamil rapidly abolished ON. OFF persisted when ON had disappeared by repeated stimulation at 0.12 train per sec. Conversely, caffeine, $50{\mu}M$ and theophylline, $10{\mu}M$ abolished OFF with only slight reduction of ON, and sodium nitroprusside decreased preferentially ON amplitude rather than OFF. Relaxation between ON and OFF was incomplete in low $Na^+$ solution. ON and OFF were not affected by the neural blockers tetrodotoxin, atropine or phentolamine, also pyrilamine and methysergide, and relaxation between ON and OFF was $Na^+$ dependent. Furthermore, ON depends on free $Ca^{++}$ and OFF is more dependent on bound or stored $Ca^{++}$.