• Korean Journal of Veterinary Service
• /
• v.17 no.3
• /
• pp.247-254
• /
• 1994

To elucidate the action of the cholinergic nerve on the isolated uterine smooth muscle of the pig, effects of electrical transmural nerve stimulation and acetylcholine were investigated on the pretreatment of the physostigmine ; cholinestrase inhibitor and atropine ; cholinergic receptor blocker from physiograph. 1. The contractile response induced by acetylcholine was responsed in the concentration of 10^{-8}$ M at first and the maximum contractility was concentration of $10^{-6}$ M. 2. The contractile response induced by electrical transmural nerve stimulation(20 V, 0.5 Msec, 20 sec) was the frequency(2-64 Hz) -dependent manner. 3. The contractile response induced by acetylcholine was completely blocked by the pretreatment with cholinergic receptor blocker, atropine and was increased by the pretrement of cholinestrase inhibitor, physostigmine. 4. The contractile response induced by electrical transmural nerve stimulation was completely blocked by the pretreatment with cholinergic receptor blocker, atropine, and was increased by the pretretment of cholinestrase inhibitor, physostigmine. These findings suggest that it was powerful excitatory action by cholinergic nerve on uterine smooth muscle of the pig.

• Journal of Chest Surgery
• /
• v.27 no.1
• /
• pp.9-14
• /
• 1994

Substance P[SP] has been known to be a peptide which may be plays a role as a neurotransmitter in central nervous system as well as peripheral autonomic nervous system. It has been reported that SP was widely distributed in the nerve of the tracheal smooth muscle and induced the muscle contraction. However, definite action mechanism of SP in the tracheal smooth muscle was not clear, yet. Thus, present experiment was performed to elucidate an effect of substance P and an action mechanism on contraction of the smooth muscle in rabbits. In order to find a neural mechanism to the effect of SP on the tracheal smooth muscle contraction, atropine sulfate, tetrodotoxin, propranol and phentolamine were administered at 10 min before the addition of SP. Otherwise,to find effect of SP antagonists on the action of SP, [D-Pro2, D-Try7,9]SP, [D-Arg1, D-Pro2, D-Trp7,9, Leu11]SP and [D-Pro4, D-Trp7,9]SP were administered as a same fashion. These following results were obtained. 1] SP induced contraction of the tracheal smooth muscle under resting condition and the contraction was increased dose-dependently. 2] Cholinergic blocker[atropine], neural blocker[tetrodotoxin] and adrenergic blocker[propranol and phentolamine] didn`t have an effect on the contractile response. 3] Three SP antagonists inhibited the contractile response. 4] Isoproterenol relaxed the contraction induced by SP. The above results suggested that SP induced contraction of the tracheal smooth muscle directly act to the smooth muscle in rabbits. The autonomic nervous system did not seem to participate in the SP action.

• YAKHAK HOEJI
• /
• v.45 no.3
• /
• pp.282-286
• /
• 2001

To investigate the different mechanism between ATP and compound 48/80 (C$_{48}$80/)-induced histamine release, we observed effects of calcium antagonists in histamine release of rat peritoneal mast cells. Verapamil and diltiazem (voltage-dependent calcium channel blocker) and TMB-8 (a blocker of intracellular calcium release) significantly inhibited ATP-induced histamine release, but did not inhibit $C_{48}$80/-induced histamine release. Econazole (a blocker of receptor-operated calcium channel) dose-dependently inhibited both ATP and $C_{48}$80/-induced histamine release, but inhibitory effect of econazole in ATP-induced histamine release was more potent than that in $C_{48}$80/-induced histamine. EGTA dose-dependently inhibited ATP and $C_{48}$80/-induced histamine release, but $C_{48}$80/-induced histamine release was slightly inhibited by high concentrations (>2 mM) of EGTA. These results suggest that ATP-induced histamine release is related to broth intracellular calcium release and extracellular calcium influx via voltage-dependent calcium channel and receptor-operated calcium channel. $C_{48}$80/-induced histamine release is related to extracellular calcium influx, especially by receptor-operated calcium channel rather than voltage-dependent calcium channel.

• Journal of the Korean Chemical Society
• /
• v.55 no.2
• /
• pp.268-278
• /
• 2011

Corrosion of aluminum in 0.1 M HCl solution in the absence and presence of ${\beta}$-blocker inhibitors (atenolol, propranolol, timolol and nadolol) was investigated using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The inhibition efficiency increased with inhibitor concentration and decreased with rise of temperature. Potentiodynamic polarization curves revealed that they acted as cathodic inhibitors. Some thermodynamic parameters were calculated and discussed. All inhibitors were adsorbed on Al surface obeying Frumkin isotherm. All EIS tests exhibited one capacitive loop which indicates that the corrosion reaction is controlled by charge transfer process. The inhibition efficiencies of all test methods were in good agreement.

• The Korean Journal of Physiology and Pharmacology
• /
• v.1 no.6
• /
• pp.783-796
• /
• 1997

The relaxation induced by stimulation of the inhibitory non-adrenergic, non-cholinergic (iNANC) nerve is mediated by the release of iNANC neurotransmitters such as nitric oxide (NO), vasoactive intestinal peptide (VIP) and adenosine triphosphate (ATP). The mechanisms of NO, VIP or ATP-induced relaxation have been partly determined in previous studies, but the detailed mechanism remains unknown. We tried to identify the nature of iNANC neurotransmitters in the smooth muscle of guinea pig ileum and to determine the mechanism of the inhibitory effect of nitric oxide. We measured the effect of NO-donors VIP and ATP on the intracellular $Ca^{2+}$ concentration$([Ca^{2+}]_i)$, by means of a fluorescence dye(fura 2) and tension simultaneously in the isolated guinea pig ileal smooth muscle. Following are the results obtained. 1. Sodium nitroprusside $(SNP:10^{-5}\;M)$ or S -nitro-N-acetyl-penicillamine $(SNP:10^{-5}\;M)$ decreased resting $[Ca^{2+}]_i$ I and tension of muscle. SNP or SNAP also inhibited rhythmic oscillation of $[Ca^{2+}]_i$ and tension. In 40mM $K^+$ solution or carbachol ($(CCh:10^{-6}\;M)$-induced precontracted muscle, SNP decreased muscle tension. VIP did not change $[Ca^{2+}]_i$ and tension in the resting or precontracted muscle, but ATP increased resting $[Ca^{2+}]_i$ and tension in the resting muscle. 2. 1H-[1,2,4]oxadiazol(4,3-a)quinoxalin-1-one $(ODQ:1\;{\mu}M)$, a specific inhibitor of soluble guanylate cyclase, limited the inhibitory effect of SNP 3. Glibenclamide $(10\;{\mu}M)$, a blocker of $K_{ATP}$ channel, and 4-aminopyridine (4-AP:5 mM), a blocker of delayed rectifier K channel, apamin $(0.1\;{\mu}M)$, a blocker of small conductance $K_{Ca}$ channel had no effect on the inhibitory effect of SNP. Iberiotoxin $(0.1\;{\mu}M)$, a blocker of large conductance $K_{Ca}$ channel, significantly increased the resting $[Ca^{2+}]_i$, and tension, and limited the inhibitory effect of SNP. 4. Nifedipine $(1\;{\mu}M)$ or elimination of external $Ca^{2+}$ decreased not only resting $[Ca^{2+}]_i$ and tension but also oscillation of $[Ca^{2+}]_i$ and tension. Ryanodine $(5\;{\mu}M)$ and cyclopiazonic acid $(10\;{\mu}M)$ decreased oscillation of $[Ca^{2+}]_i$ and tension. 5. SNP decreased $Ca^{2+}$ sensitivity of contractile protein. In conclusion, these results suggest that 1) NO is an inhibitory neurotransmitter in the guinea pig ileum, 2) the inhibitory effect of SNP on the $[Ca^{2+}]_i$ and tension of the muscle is due to a decrease in $[Ca^{2+}]_i$ by activation of the large conductance $K_{Ca}$ channel and a decrease in the sensitivity of contractile elements to $Ca^{2+}$ through activation of G-kinase.

• Korean Journal of Clinical Pharmacy
• /
• v.12 no.2
• /
• pp.96-100
• /
• 2002

• Design & Manufacturing
• /
• v.6 no.2
• /
• pp.6-11
• /
• 2012

A counter shaft gear is an important part in the transmission system of vehicle. Its shape is relatively complicated and should meets high strength. Traditionally the counter shaft gear has been manufactured as follows; a spline body is firstly machined for teeth and then attached to the main gear body by frictional welding, and finally is finished by grinding. Therefore it is necessary to develop a new manufacturing technology eliminating both frictional welding and grinding processes. In this study, a new hot forging process was proposed and designed so that the spline body with teeth and main gear body are formed as one body. Finite element simulations and experimental works were peformed for design of forging processes to get the quality final precision-forged product. Consequently the most suitable blocker process could be obtained.

• The Korean Journal of Pain
• /
• v.13 no.1
• /
• pp.115-118
• /
• 2000

Stellate ganglion block is most commonly used in pain clinic because it is an easy procedure and it has broad indications reported that Angina pectoris, tachyarrhythmia and long QT syndrome (LQTS) are indicated. LQTS is a disorder of the abnormalities of cardiac sympathetic innervation and of myocardial repolarization. LQTS is characterized by marked prolongation of the QT interval, often manifestating as syncope, seizures, or sudden death due to polymorphic ventricular tachyarrhythmia known as torsades de pointes. Treatment of symptomatic patients usually begin with beta blocker. The elective treatment of LQTS patients unresponsive to beta blocker is the left cardiac sympathetic denervation. We report a case of LQTS patient who had received stellate ganglion block.

• Current Optics and Photonics
• /
• v.2 no.1
• /
• pp.23-26
• /
• 2018

Optical-layer restoration has been demonstrated with a wavelength-blocker (WB) -based reconfigurable optical add/drop multiplexer (ROADM). Two $2{\times}2$ optical switches with a control circuit were placed before and after a WB-based ROADM to provide automatic path restoration under fiber-failure conditions. Using the proposed node configuration, a 3-node self-healing ring (SHR) network has been implemented to demonstrate the feasibility of the automatic optical-layer restoration. From the results, the restoration time was measured to be ~4 ms under fiber-failure conditions, without any additional power penalty in receiver sensitivity.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 2001.11a
• /
• pp.96-96
• /
• 2001

This study was attempted to investigate the effect of cromakalim(CRK). $K^{-}$ channel opener, and glibenclamide(GLY), $K^{-}$ channel blocker, on intestinal function of rabbit. CRK supressed the tension and spontaneous movement of intestinal strips. Such CRK strengthened the tension and spontaneous movement of strips potentiated by acetylcholine, whereas more attenuated those weakened by dopamine. GLY augmented the tension, did not affect to the spontaneous movement of strips. GLY inhibited the acetylcholine-potentiated responses of tension and spontaneous movements in intestinal strips. GLY blocked the weakened responses of tension, while did not affect to the dopamine-weakened responses of spontaneous movements in intestinal strips. The present studies suggest that $K^{-}$ channel opening suppresses intestinal movements, whereas it's blockade enhances intestinal movements in rabbit.abbit.