• The Korean Journal of Physiology
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• 제25권2호
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• pp.133-146
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• 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 Korean Journal of Physiology
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• 제24권1호
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• pp.1-13
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• 1990

기니피그 유문동 부위를 절제한 뒤 점막층을 박리하고 윤상근 주행방향으로 길이 10 mm, 너비 2 mm 되는 조직 절편을 만들어 수평형 실험용기에 넣어 핀으로 고정하였다. 유리미세전극을 세포내에 삽입하여 서파를 기록하면서 조직양편에 설치한 백금자극전극(직경 0.5 mm)에 강도 $10{\sim}50V$, 기간 $50{\sim}100\;{\mu}s$ 되는 자극파를 주어 신경-근 부위의 접합부 전압을 기록하여 다음과 같은 결과를 얻었다. 1) 위저부에서는 흥분성 접합부 전압이, 유문동에서는 억제성 접합부 전압이 기록되었고 유문동의 억제성 접합부 전압은 atropine($10^{-6}\;M)$과 guanethidine$(5{\times}10^{-6}\;M)$을 동시 처치했을 때 영향을 받지 않았다. 2) 세포외 $Ca^{2+}$ 농도를 높였을 때(7 mM)는 억제성 접합부 전압의 크기가 증가하고 세포외 $Mg^{2+}$ 농도를 높였을 때(5 mM)와 verapamil($10^{-5}\;M$)을 주었을 때는 억제성 접합부 전압의 크기가 감소하였다. 3) 아데노신을 투여하였을 때와 ATP를 투여했을 때는 모두 억제성 접합부 전압의 크기가 감소하였다. 4) 5-HT$(10^{-6}\;M)$을 투여했을 때는 서파크기에는 변화없이 억제성 접합부 전압의 크기만 감소하였고 5-HT type 2 길항제인 ketanserin$(5{\times}10^{-6}\;M)$을 투여했을 때는 서파크기는 현저히 감소한 반면 억제성 접합부 전압크기는 변화가 없었다. 이상의 결과로부터 유문동에서 기록되는 억제성 접합부 전압은 비아드레날린, 비콜린 동작성 신경에 의해 유발되며 $Ca^{2+}$은 비아드레날린 비콜린 동작성 신경에서 신경흥분전달물질의 유리를 촉진시키고 분비된 신경흥분전달물질로 인해 $Ca^{2+}$ 의존성 $K^{+}$ 통로가 활성화되어 억제성 접합부 전압의 크기를 증가시킨다고 사료된다.

• 대한수의학회지
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• 제35권3호
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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 Physiology
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• 제21권2호
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• pp.225-239
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• 1987

The effects of adenosine on the mechanical contractions and electrical activities were investigated in guinea-pig stomach. Spontaneous contractions of the antral region were recorded with force transducer, and the phasic contractions of fundic region were induced by electrical field stimulation. Electrical responses of smocth muscle cells were recored using glass capillary microelectrodes filled with 3M-KCl. Field stimulation was applied transmurally by using a pair of platinum wire (0.5 mm in diameter) placed on both sides of tissue. All experiments were performed in tris-buffered Tyrode solution which was aerated with 100% $O_2$ and kept at $35^{\circ}C$. The results obtained were as follows. 1) Adenosine suppressed the spontaneous contractions of antrum in a dose-dependent manner. 2) The inhibitory effect on antral spontaneous contractions was not influenced by the administration of guanethidine $(5{\times}10^{-6}\;M)$ and atropine $10^{-6}\;M$, or in the presence of dipyridamole $10^{-7}\;M$. 3) The phasic contractions of fundus induced by electrical field stimulation, which disappeared rapidly by the addition of tetrodotoxin $(3{\times}10^{-7}\;M)$, were potentiated by adenosine in the presence of guanethidine. 4) Adenosine decreased the amplitude and the maximum rate of rise of slow waves, and the increased amplitude and rate of rise evoked in the high calcium solution or in the presence of TEA were decreased by adenosine. 5) The non-adrenergic, non-cholinergic inhibitory junction potential (IJP) was inhibited by adenosine in the antral region, while the excitatory junction potential (EJP) in the fundic region was potentiated. From the above results, the following conclusions could be made. 1) Adenosine suppresses the spontaneous contractions of antrum strip by the decrease in amplitude and rate of rise of slow waves. 2) The release of neurotransmitter(s) from non-adrenergic, non-cholinergic nerve terminals is inhibited by adenosine.

• International Journal of Oral Biology
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• 제37권2호
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• pp.63-68
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• 2012

It has been documented that SPA0355 exerts antiinflammatory effects via the inhibition of nuclear factor-kappaB activation. In present study, we investigated the inhibitory effects of SPA0355 on periodontitis in an animal model. Periodontitis was induced by ligation of the cervix of the 1st molar in the left mandible in rats. After ligature, the rats were randomly divided into four groups and topically applied with SPA0355 (0.5, 1, and 2%) or the vehicle alone once daily for 10 days. Body weight and food intake were measured daily throughout the experimental period. At day 10 post-ligature, the infiltration of inflammatory cells and distance of the cementoenamel junction (CEJ) to the alveolar bone crest (ABC) in the distal area of ligatured tooth were estimated histopathologically. No changes in body weight or food intake were found between the control and SPA0355 groups. The degree of inflammation was decreased in all three SPA0355 application groups. A decrease CEJ-ABC distance was observed in the 0.5% and 1% SPA0355 groups. These results indicate that SPA0355 inhibits the infiltration of inflammatory cells and alveolar bone resorption and suggests its potential as a therapeutic agent for periodontitis.

• 생명과학회지
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• 제20권4호
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• pp.528-534
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• 2010

본 연구에서는 흑마늘 열수 추출물(ABG)의 암세포 전이억제 효능을 검정하였다. AGS AGS 인체위암세포의 이동성과 침윤성을 억제하였으며, 이는 TER의 증가와 연관성이 있었다. 또한 ABG에 의한 AGS 위암세포의 침윤성 억제는 TIMPs 발현 증가에 의한 MMPs의 발현 및 활성 저하에 의한 것임을 알 수 있었다. 아울러 AGS 위암세포에서 과발현을 나타내는 TJ 단백질인 claudins의 발현 저하 등이 ABG의 항전이 효과에 연관되어 있음을 알 수 있었다. 이상의 결과는 흑마늘 열수 추출물이 단순한 암세포의 증식억제를 통한 암예방 및 항암활성 뿐만 아니라 암세포의 전이 또한 효과적으로 억제할 수 있음을 보여주며, 이와 연관된 보다 구체적인 분자세포생물학적 접근 및 in vivo 연구의 필요성이 요구됨을 의미한다.