• Biomolecules & Therapeutics
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• v.5 no.4
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• pp.369-375
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• 1997

General pharmacological effects of SB-31$^{R}$, the extracts of Pulsatilla koreana, were investigated in mice, rats and guinea-pigs. Intravenous injection of SB-31 (3 and 6 ml/kg) produced almost no effect on central nervous system no effects on the general symptom and behaviors of mice, spontaneous locomotor activity, pentobarbital- induced sleeping time , rotared performance , electroshock and pentylenetertrazole -induced seizures, acetic acid-induced writhing and normal body temperature in mice. SB-31 showed little effects on the spontaneous movement of the isolated ileum and contraction induced by agonists in isolated ileum, suggesting no influence on autonomic nervous system. Administration of SB-31 also did not show any effect on blood pressure in conscious rats. However, a slight decrease in heart rate was observed at high doses (6 and 10 ml/kg) of SB-31 in conscious rats. Similarly, a slight increase in respiratory rate was observed at 6 m1/kg of SB-31 in anesthetized rats. SB-31 did not produce any effect at the dose of 3 ml/kg, but showed a tendency to increase the urinary volume at 6 ml/kg, and produced a decrease in urinary excretions of N $a_{+}$and $K_{+}$at 6 ml/kg. However, transport capacity within the gastrointestinal tract and the secretion of the gastric juice were not influenced by 6 ml/kg of SB-31. In conclusion, these results suggest that SB-31 did not pro-duce any acute effects on the central nervous system, autonomic nervous system, respiratory and circulatory systems, digestive system and kidney function at the dose of below 3 ml/kg.ml/kg.

• The Korean Journal of Physiology and Pharmacology
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• v.25 no.6
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• pp.525-532
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• 2021

We have investigated the relative roles of α₁-adrenoceptors and purinoceptors in contractions to low and high frequency stimulation of the mouse vas deferens, in terms of the time course of responses. In separate experiments, isometric contractile responses were obtained to 10 pulses at 1 Hz and 40 pulses at 10 Hz. Responses to 1 Hz stimulation consisted of a series of discrete peaks. The α_1A-adrenoceptor antagonist RS100329 (10^-9M-10^-7M) significantly reduced the response to the first pulse, the α_1D-adrenoceptor antagonist BMY7378 (10^-7M-10^-6M) significantly reduced the response to the first two pulses, and the non-selective α₁-adrenoceptor antagonist prazosin (10^-8M) reduced the response to the first 4 pulses at 1 Hz. Responses to 10 Hz stimulation consisted of an early peak response and a maintained plateau response. RS100329 significantly reduced the peak response but did not significantly affect the plateau response. Prazosin, significantly reduced both the peak and plateau responses. The α_1A-adrenoceptor antagonist RS17053 in high concentrations reduced mainly the plateau response leaving a clear early peak response. The plateau response of contraction was almost abolished by the purinoceptor antagonist suramin. These results suggest that there is a relatively minor early α_1D-adrenoceptor and a larger early α_1A-adrenoceptor component to stimulationevoked contractions of mouse vas deferens, but the major α₁-adrenoceptor component is revealed by prazosin to be α_1B-adrenoceptor mediated. α_1B-Adrenoceptor activation probably facilitates contractions mediated by other α₁-adrenoceptors and by purinoceptors. These results suggest that combined non-selective α₁-adrenoceptor blockade, particularly α_1B-adrenoceptor blockade, in addition to P2X1-purinoceptor blockade is useful in reducing male fertility.

• The Korean Journal of Physiology
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• v.21 no.2
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• pp.241-257
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• 1987

The effects of external $Ca^{2+}$ and $Ca^{2+}-antagonists$ on the spontaneous contractions and electrical activities were investigated in guinea-pig stomach in order to clarify the mechanism for the generation of slow waves. Electrical responses of circular smooth muscle cells were recorded using glass capillary microelectrodes filled with 3 M KCl. 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) The amplitude of spontaneous contractions was maximal at around 2-4 mM $Ca^{2+}$, whereas their frequency was inversely related with external $Ca^{2+}$ within the range of 0.5 to 16 mM $Ca^{2+}$. 2) Verapamil suppressed the amplitude of spontaneous contraction in a dose-dependent manner, while the frequency of spontaneous contractions was almost not changed over the whole concentration of verapamil $(0.01{\sim}5\;mg/l)$. 3) Manganese increased both the amplitude and the frequency of spontaneous contractions dose-dependently in low $Mn^{2+}$ (below 0.05 mM $Mn^{2+}$), while their amplitude and frequency were decreased in high $Mn^{2+}$ (above 0.1 mM $Mn^{2+}$). 4) The ampltude and maximum rate of rise of slow waves were incrased in high $Ca^{2+}$ solution. In $Ca^{2+}-free$ solution, the spontaneous contractions recorded simultaneously with slow waves ceased and tonic contraction ($Ca^{2+}-free$ contracture) was developed in parallel with membrane depolarization and the disappearance of slow waves. 5) Verapamil (1 mg/1) decreased the amplitude and maximum rate of rise of slow waves and it depolarized the membrane by about 6 mV, whereas the frequency of slow waves was not affected by verapamil. 6) Manganese showed different characteristic effects between low and high $Mn^{2+}$ on the slow waves: In low $Mn^{2+}$ (0.05 mM $Mn^{2+}$), the initial rapid increases and the subsequent gradual decreases in three parameters of slow waves (amplitude, rate of rise, and frequency of slow waves) till a new steady state were observed. However, in high $Mn^{2+}$ (0.5 mM $Mn^{2+}$) slow waves disappeared and membrane was depolarized. From the above results, the following conclusions could be made: 1) $Ca^{2+}$ is necessary for a generation of the slow waves, even though it is small amount. 2) Verapamil suppresses the spontaneous contractions of gastric antral strip by the decreases in amplitude and maximum rate of rise of slow waves, while this drug does not block the $Ca^{2+}-channel$ involved in the generation of slow waves. 3) Manganese has dual actions on the $Ca^{2+}-channels$; the $Ca^{2+}-channel$ involved in the generation of slow waves (or Na-Ca exchange system) or the channel for the generation of spike potentials are stimulated by a low concentration of $Mn^{2+}$, while both the $Ca^{2+}$. Channels are blocked by high concentration of $Mn^{2+}$.

• The Korean Journal of Physiology
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• v.23 no.2
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• pp.263-275
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• 1989

Mechanical contractions and electrical activities of the fundic longitudinal and antral circular muscle fibers were investigated in order to elucidate topical differences of gastric motility. K-induced contracture was produced by exposure of muscle strips to high K Tyrode solution. Membrane potential and mechanical contraction were simultaneously recorded by conventional glass microelectrode method and single sucrose-gap technique. All experiments were performed in tris-buffered Tyrode solution which was aerated with $100%\;O_2\;and\;kept\;35^{\circ}C$. The results obtained were as follows: 1) The resting membrane potential of circular muscle cells in the antral region was about 10 mV more negative than that in the fundic region. 2) The membrane potentials decreased almost linearly as the extracellular KCI concentration was increased both in antral circular muscle cells and in fundic longitudinal muscle cells. 3) The thresholdal K concentration of K-contracture was 15 mM (membrane potential, -48 mV) for the antral circular muscle strip and 20 mM for the fundic longitudinal muscle cells. 4) The ratio of membrane permeability coefficient for $Na^+\;and\;K^+,\;P_{Na}/P_K\;({\alpha})$ was 0.065 for antral circular muscle cells and was 0.108 for fundic longitudinal muscle cells. 5) K-contracture of antral and fundic smooth muscle strips showed the contracture composed of phasic and tonic components. The amplitude of the phasic component increased sigmoidally in a dose-dependent manner, whereas that of the tonic component was maximal at a concentration of 40 mM KCI and at the concentrations above or below 40 mM KCI the amplitude was reduced. 6) The inverse relationship between the amplitude of tonic component and extracellular KCI concentration in the range of 40 to 150 mM KCI was more prominent in the antral circular muscle strip than in the fundic longitudinal muscle strip, where the amplitude of the tonic component decreased less steeply and was maintained higher at the same high K concentrations. 7) The tonic component was totally dependent on the external $Ca^{2+}$ and completely abolished by verapamil, while tile phasic component was far less dependent on the external $Ca^{2+}$ and partially suppressed by verapamil. From the above results, the following conclusions could be made. 1) The phasic component of K-contracture is produced both by intracellular $Ca^{2+}$ mobilization and by $Ca^{2+}$-influx from outside, while the tonic component is generated and maintained by the $Ca^{2+}-influx$ through the potential-dependent $Ca^{2+}$ channel. 2) The mechanism of reducing the free $Ca^{2+}$ concentration in the myoplasm seems to be more developed in the antral circular muscle than in the fundic longitudinal muscle. 3) The lower resting membrane potential of the fundic longitudinal muscle cell reflects a relatively high $P_{Na}/P_K$ ratio of about 0.108.

• The Journal of Korean Academy of Prosthodontics
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• v.34 no.2
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• pp.320-334
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• 1996

Dental cast and die materials are essential material using in almost dental prsthodontic procedure and it's most important requirement is accuracy for reqorducing the oral anatomical structures. In this study, 5 abutments A, B, C, D, E were fabricated on the metal master model to simulate the arch form and specimens were poured with 4 cast materials. Inter-abutment distances, A-B, A-C, A-D, A-E, B-C, B-D were calculated using the photo-scanning and the deviations from the metal master model were also evaluated. The results were as follows; 1. The distance between A-B, A-C, A-D, A-E, B-C, B-D of the abutments A, B, C, D, E of each cast material was calculated. And after comparing the deviations between the metal master model. $Fujirock^{(R)}$ showed the lowest value with $0.20{\pm}0.22mm$, and the deviation increased in the order of $Suprastone^{(R)}$, Epoxy $Die^{(R)}$, Die $Keen^{(R)}$. There was significant difference between $Fujirock^{(R)}$ and Epoxy $Die^{(R)}$, Die $Keen^{(R)}$. 2. In each calculation area, the difference in measurements between cast material and metal master model showed singificant difference between A-B and Cross arch measure-ments of A-D, B-D, A-E(p<0.05). 3. The difference in measurements between cast material and metal master model in the A-B area showed $Fujirock^{(R)}$ to be the lowest with $0.05{\pm}0.04$mm and increased in the order of Die $Keen^{(R)}$, $Suprastone^{(R)}$, Epoxy $Dies^{(R)}$. There was significant difference between $Fujirock^{(R)}$ and $Suprastone^{(R)}$, Epoxy $Die^{(R)}$ (p<0.05). 4. The difference in measurements between cast material and metal master model in the B-C area showed $Fujirock^{(R)}$ to bo the lowest with $0.17{\pm}0.11$mm and increased in the order of $Suprastone^{(R)}$, Die $Keen^{(R)}$, Epoxy $Dies^{(R)}$. There was significant difference between $Fujirock^{(R)}$ and Die $Keen^{(R)}$, Epoxy $Die^{(R)}$(p<0.05). 5. The difference in measurements between cast material and metal master model in the B-D area showed $Fujirock^{(R)}$ to bo the lowest with $0.13{\pm}0.07$mm, Epoxy $Dies^{(R)}$and increased in the order of $Suprastone^{(R)}$, Die $Keen^{(R)}$. There was significant difference between $Fuji-rock^{(R)}$ and Die Keen(p<0.05). 6. In this experiment, Epoxy $Dies^{(R)}$ showed mean contraction in every calculation area. And when reconstruction cross arch restorations it is thought that distortion should be considered in every cast material.

• Korean Journal of Food Science and Technology
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• v.25 no.2
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• pp.185-190
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• 1993

Tilapia cultured in fresh water were acclimated in sea water with daily increase of $5%_{\circ}$ of salinity and it was completely terminated at the 7th day (0 week). Each three tilapia acclimated were examined weekly based from 0 week to elucidate changes of chloride cells in gill, mineral contents and physical properties in muscle and biochemical characteristics in myofibrils. Chloride cells existed in gills were gradually developed in number and size by acclimation to sea water and became to almost constant state at the third week. Shearing value, compressing strength and content of minerals such as Mg, Na and K in muscle were showed remarkable increase by acclimation to sea water in comparison to those of muscle from tilapia reared in fresh water. Myofibrillar $Mg^{2+}-,\;Ca^{2+}-$ and $K^+(EDTA)-ATPase$ activities of tilapia acclimated in sea water also increased showing significant statistic difference (p<0.01) from those of tilapia reared in fresh water However. thermostability of myofibrils was dropped by acclimation to sea water. The increase of shearing value and compressing strength in the muscle of tilapia by acclimation to sea water would be attributed to the increase of myofibrillar ATPase activities which act to accelerate the decomposition rate of ATP. Therefore, it is suggested that this phenomenon associated with muscle contraction could be brought an improvement of texture of tilapia acclimated in sea water.

• The Korean Journal of Pharmacology
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• v.26 no.1
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• pp.25-33
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• 1990

The responsiveness of various arterial smooth muscles isolated from rabbit to peptide YY (PYY) and the calcium source responsible for the muscles to contract were studied in vitro. PYY contracted the muscle strips of femoral, basilar and common iliac arteries more sensitively than renal, superior mesenteric and common carotid arteries. Common carotid and renal arteries were less sensitive to PYY $(p{\leqslant}0.05)$ than to NE; and basilar artery was more sensitive to PYY$(p{\leqslant}0.01)$ than to NE. A calcium channel blocker, verapamil and an inhibitor of intracellular calcium release, 3, 4, 5-Trime-thoxybenzoic arid 8-(diethylamino)octyl ester [TMB-8] significantly $(p{\leqslant}0.001)$ suppressed the concentration-response of the strips from femoral artery to PYY. When both verapamil and TMB-8 existed in normal PSS, the concentration-response to PYY was inhibited almost completely; and a similar suppression was observed when the muscle was incubated in calcium-free, ethyleneglycol-bis-(beta-aminoethyl ether)N,N,N',N'-tetraacetic acid [EGTA] containing PSS. The results of these experiments suggest that increased PYY activity in circulation may result in the more sensitive increase in the intracranial vascular resistance and the cerebral arterial pressure than the increased sympathetic activity and that both intra- and extracellular calcium are to be utilized for the PYY-induced contraction on arterial smooth muscle.

• Korean Journal of Ichthyology
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• v.12 no.1
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• pp.38-45
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• 2000

Depending on the fish species the vascular tone is distinctively regulated by numerous vasoactive substances. In most fish species the regulatory role of autonomic neurotransmitters and other vasoactive substances are not well defined. This research was designed to delineate the regulatory role of various endogenous autonomic neurotransmitters known to be important in mammalian vascular systems on isolated Israeli carp ventral aorta. Acetylcholine(ACh) contracted the aorta regardless of the pre-existing level of vascular tone, and the contraction was almost completely abolished by a cholinergic-muscarinic antagonist atropine. Endogenous, multiple receptor ($\alpha$ and $\beta$)-acting adrenergic agonist epinephrine (Epi) relaxed the vessel in the presence and absence of the pre-existing tones. Another endogenous multiple receptoracting agonist norepinephrine (NE) weakly contracted the aorta in non-preconstrcted state, but the response was reversed to relaxation when preconstricted. Isoproterenol, ${\alpha}\;{\beta}$ adrenergic receptor agonist, was a potent vasodilator whereas an ${\alpha}_1$ agonist phenyephrine was a contractor. The ${\alpha}_2$ adrenergic receptor agonist clonidine has not any significant effect in altering the vascular tone. The vasorelaxing action of Epi, NE and isoproterenol was significantly attenuated by $\beta$ receptor antagonist propranolol. These results imply that ACh may primarily play a contractor role via muscarinic receptor activation while adrenergic agonists, Epi and NE, are relaxants through activation of $\beta$ adrenergic receptors in vivo.

• The Korean Journal of Physiology and Pharmacology
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• v.24 no.6
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• pp.503-516
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• 2020

KCNQ family constitutes slowly-activating potassium channels among voltage-gated potassium channel superfamily. Recent studies suggested that KCNQ4 and 5 channels are abundantly expressed in smooth muscle cells, especially in lower urinary tract including corpus cavernosum and that both channels can exert membrane stabilizing effect in the tissues. In this article, we examined the electrophysiological characteristics of overexpressed KCNQ4, 5 channels in HEK293 cells with recently developed KCNQ-specific agonist. With submicromolar EC₅₀, the drug not only increased the open probability of KCNQ4 channel but also increased slope conductance of the channel. The overall effect of the drug in whole-cell configuration was to increase maximal whole-cell conductance, to prolongate the activation process, and left-shift of the activation curve. The agonistic action of the drug, however, was highly attenuated by the co-expression of one of the β ancillary subunits of KCNQ family, KCNE4. Strong in vitro interactions between KCNQ4, 5 and KCNE4 were found through Foster Resonance Energy Transfer and co-immunoprecipitation. Although the expression levels of both KCNQ4 and KCNE4 are high in mesenteric arterial smooth muscle cells, we found that 1 μM of the agonist was sufficient to almost completely relax phenylephrine-induced contraction of the muscle strip. Significant expression of KCNQ4 and KCNE4 in corpus cavernosum together with high tonic contractility of the tissue grants highly promising relaxational effect of the KCNQ-specific agonist in the tissue.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.12
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• pp.1568-1575
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• 2008

This study was performed to determine alleviating effects of green tea (GT) on the N-nitrosodimethylamine (NDMA) toxicity to mucins in the rat lingual salivary glands. Sprague-Dawley rats were divided into five groups: untreated (Control), one week-NDMA administrated (NDMA), one week-GT administrated after NDMA for one week (NDMAGT), one week-NDMA administrated with GT (GTNDMA), and one-week NDMA administrated with GT after GT for one week (GTGTNDMA). The mucin properties were elucidated by periodic acid Schiff (PAS) reaction, alcian blue (AB) pH 2.5, AB pH 2.5-PAS, aldehyde fuchsin (AF) pH 1.7-AB pH 2.5, and high iron diamine (HID)-AB pH 2.5 staining. The lingual von Ebner's glands of NDMA group showed some changes such as contraction and destruction of the serous acini, decrease and disappearance of the cytoplasmic granules, vacuolation of cytoplasm, and the mucigenous duct cells. Also, in the lingual mucous glands, enlarged lumens, fused acini, disappearance of granules, vacuolation of cytoplasm, and mucigenous duct cells were observed. All the GT administrated groups had a tendency to recover. GTGTNDMA group recovered almost up to the state of the control group. The lingual von Ebner's glands of NDMA group showed a decrease of neutral mucin and the lingual mucous glands showed a decrease of both neutral and acidic mucins decreased in comparison with control group, although mucous acini secreting strong sulfomucin decreased while those secreting non-sulfomucin (sialomucin) increased. All the GT administrated groups had a tendency to recover. The degree of recovery in the GTNDMA group was stronger than in NDMAGT group and that of the GTGTNDMA group was almost up to the state of the control group. Plus, lingual von Ebner's glands of GTGTNDMA group contained much more neutral mucin than in the control group. In conclusion, it is suggested that NDMA exhibit the toxicity which affects on the mucin properties and which green tea alleviates.