• 대한의생명과학회지
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• 제13권3호
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• pp.197-206
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• 2007

P2X receptors are membrane-bound ion channels that conduct $Na^+,\;K^+$, and $Ca^{2+}$ in response to ATP and its analogs. There are seven subunits identified so far ($P2X_1-P2X_7$). $P2X_2$ receptors are known to be expressed in a wide range of organs including brains and adrenal grands. PC12 cells are originated from adrenal grand and differentiated by nerve growth factor or pituitary adenylate cyclase activating poly peptide (PACAP). Previous studies indicate that $P2X_2$ receptor activation in PC12 cells couples to $Ca^{2+}-dependent$ release of catecholamine and ATP. It is known that acidic pH potentiates ATP currents at $P2X_2$ receptors. This leads to a hypothesis that $P2X_2$ receptors may play an important role in PC12 cell differentiation, one of the characteristics of which is neurite outgrowth, induced by the hormones under lower pH. In the present study, we isolated several clones which potentiate neurite outgrowth by PACAP in acidic pH (6.8), but not in alkaline pH (7.6). RT-PCR and electrophysiology data indicate that these clones express only functional $P2X_2$ receptors in the absence or presence of PACAP for 3 days. Potentiation of neurite outgrowth resulted from PACAP (100 nM) in acidic pH is inhibited by the two P2X receptor antagonists, suramin and PPADS ($100\;{\mu}M)$ each), and exogenous exprerssion of ATP-binding mutant $P2X_2$ receptor subunit ($P2X_2[K69A]$). However, acid sensing ion channels (ASICs) are not involved in PACAP-induced neurite outgrowth potentiation in lower pH since treatments of an inhibitor of ASICs, amyloride ($10\;{\mu}M$), did not give any effects to neurite extension. The vesicular proton pump ($H^+-ATPase$) inhibitor, bafilomycin (100 nM), reduced neurite extension indicating that ATP release resulted from $P2X_2$ receptor activation in PC12 cells is needed for neurite outgrowth. These were confirmed by activation of mitogen activated protein kinases, such as ERKs and p38. These results suggest roles of ATP and $P2X_2$ receptors in hormone-induced cell differentiation or neuronal synaptogenesis in local acidic environments.

• The Korean Journal of Physiology
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• 제18권2호
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• pp.139-150
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• 1984

Vanadate의 회장 평활근에 대한 수축작용이 Na-K-ATPase를 억제하기 때문인지를 구명하기 위하여 Na-K-ATPase를 억제하는 ouabain과의 작용의 차이를 관찰한 결과 다음과 같은 결론을 얻었다. 1) Ouabain에 의해 나타나는 수축은 2중 peak를 나타내었으나 vanadate 의해서는 단일 Peak만을 보였다. 2) Ouabain에 의한 수축은 atropine$(2{\times]10^{-6}M)$에 의해 강력하게 억제되었으나 vanadate의 작용은 영향을 받지 않았다. 3) Ouabain에 의한 수축은 vanadate에 비해 외부의 $Ca^{++}4농도 및 Ca-길항제에 대해 민감하게 영향을 받았다. 4) 용액내 $Na^+$이 없을때 혹은 고농도의 $K^+$존재하에서 ouabain에 의한 수축반응은 거의 나타나지 않았으나 vanadate에 의한 수축은 영향을 받지 않았다. 5) Vanadate에 의한 수축은 ouabain 존재시에 더욱 증가되었다. 6) 3시간동안 incubation한 결과 vanadate는 ouabain과 달리 세포내 $Na^+$의 농도에 영향을 미치지 못하였다. 이상의 결과로 보아 ouabain과 vanadate는 서로 다른 기전에 의해 회장 평활근에서 수축반응을 유발시키는 것으로 추측된다.

• Clinical and Experimental Pediatrics
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• 제58권9호
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• pp.347-353
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• 2015

Purpose: The purpose of this study was to evaluate the efficacy and safety of Montelukast sodium in the prevention of bronchopulmonarydysplasia (BPD). Methods: The Interventional study was designed as a multicenter, prospective, and randomized trial, with open labeled and parallel-experimental groups, 66 infants were enrolled and allocated to either the case group (n=30) or the control group (n=36) based on gestational age (GA). Infants in the case group were given Montelukast sodium (Singulair) based on their body weight (BW). Zero week was defined as the start time of the study. Results: The incidence of moderate to severe BPD was not different between the groups (case group: 13 of 30 [43.3%] vs. control group: 19 of 36 [52.8%], P=0.912). Additionally, secondary outcomes such as ventilation index, mean airway pressure and resort to systemic steroids were not significantly different. There were no serious adverse drug reactions in either group, and furthermore the rate of occurrence of mild drug related-events were not significantly different (case group: 10 of 42 [23.8%] vs. control group: 6 of 48 (15.8%), P=0.414). Conclusion: Montelukast was not effective in reducing moderate or severe BPD. There were no significant adverse drug events associated with Montelukast treatment.

• 대한약리학회지
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• 제32권1호
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• pp.31-37
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• 1996

허혈전처치(IP)의 히혈-재관류손상에 대한 심근 보호작용의 기전을 규명하기 위한 일환으로 denosine에 의한 PKC자극이 허혈전처치의 주요 기전으로 작용할 가능성을 조사하였다. 흰쥐 적출심장의 Langendorff 관류 표본에서 실험적인 허혈(30분)-재관류(20분)손상을 유도하였고, 허혈전처치는 허혈-재관류 손상 유도 전에 5분 허혈-5분 재관류를 3회 반복하여 시행하였다. 심근 손상의 지표로 심수축기능, 세포질효소 유출을 측정하였다. Adenosine이 허혈전처치의 심보호 효과에 관여하는지를 관찰하기 위하여 adenosine수용체 억제제인 8-(p-sulfophenyl)-theophylline(SPT), Xanthine amine congener(XAC) 및 8-cyclopentyl-1,3-dipropylxanthine (DPCPX)을 허혈전처치 유도 전에 투여하였다. 또한 PKC가 허혈전처치의 세포내 매개인자로 관여 할 가능성을 관찰하기 위하여 PKC활성 억제제인 polymyxin B 및 chelerythrine과 PKC translocation 억제제인 colchicine을 허혈전처치 유도 전에 투여하였다. 연구성적은 다음과 같다. 1) 허혈전처치는 허혈재관류 심장의 심기능의 저하를 현저히 회복시켜 심기능 회복률은 75%에 달하였다. 2) 허혈-재관류 심장에서 lactate dehydrogenase유출증가는 허혈전처치에 의해 현저히 저하되었다. 3) Adenosine 비선택적 차단제인 SPT와 Al 선택적 차단제인 DPCPX 및 XAC의 투여가 허혈전처치에 의한 심기능회복 및 LDH 유출 감소에 영향을 미치지 않았다. 4) PKC활성 억제제인 polymyxin B 와 chelerythrine을 처치시 히혈전처치 심장의 심기능 회복률이 현저히 감소되었으며 LHD 유출 역시 대조군 심장의 수준으로 증가하였다. 5) PKC translocation을 방해하는 colchicine도 허혈전처치의 심보호 효과를 억제시켰다. 이상의 결과들로부터 adenosine은 흰쥐 심장에서 허혈전처치의 심보호효과에 중요한 세포외 매개물질로 작용할 가능성이 희박하며, PKC는 흰쥐 심장에서 허혈전처치시 세포내 매개 인자로 관여하여 허혈전처치에 의한 심보호효과에 중요한 역할을 할 수 있으리라 사료된다.

• The Korean Journal of Physiology and Pharmacology
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• 제1권3호
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• pp.325-335
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• 1997

Evidence for the existance of at least two subclasses of renal adenosine receptors has been presented. N-6-cyclohexyladenosine (CHA) is a relatively selective $A_1$ adenosine agonists, whereas 5'-N-ethylcarboxamidoadenosine (NECA) acts as a preferential agonist of $A_2$ adenoisne receptor. N6-(L-2-phenylisoproryl)-adenosine (PIA) almost unselectively activates both $A_1\;and\;A_2$ adenosine receptors at micromolar concentrations. During the characterization of adenosine receptor in the kidney, we have discovered a novel phenomenon, that is, an intramuscular administration of CHA for 3 days caused a diuresis and a suppression of urinary concentrating ability. To further characterize this novel phenomenon, an intramuscular administration of adenosine and other adenosine angonists, PIA and NECA, and prior treatment of adenosine antagonists, caffeine, theophylline and 1,3-diethyl-8-phenyl-xanthine (DPX) were performed. Systemic administration of CHA, PIA, and NECA for 3 days caused a suppression in heart rate, blood pressure and general motor activity without change in rectal temperature. Systemic administration of CHA, 0.5, 1 and 2 mg/kg/day, for 3 days caused a dose-dependent increase in urine volume and decrease in urinary osmolarity and free water reabsorption. This phenomenon was reversible and repeatable. Administration of adenosine (40 mg/kg/day) produced no apparent effect on the renal function, whereas PIA (2 mg/kg/day) produced an similar effect to CHA on the renal function. Systemic adminstration of NECA, 0.025, 0.05 and 0.25 mg/kg/day, for 3 days caused a dose-dependent increase in urine volume and dose-dependent increases in excreted amount of creatinine, urinary osmolarity and free water reabsorption. These renal effects of adenosine agonist were maximum at second day during the drug administration. In terms of increase in urine volume and the suppression of urinary concentrating ability, NECA was potent than CHA. Prior treatment of caffeine (50 mg/kg/day) or theophylline (50 mg/kg/day) abolished the diuretic effect of CHA, whereas DPX (50 mg/kg/day) did not affect the CHA effect. CHA, 0.5 mg/kg/day, produced no change in plasma renin activity and plasma levels of aldosterone, epinephrine, and norepinephrine. These results suggest that this novel phenomenon produced by an activation of renal adenosine receptors plays an important role in urinary concentrating mechanism.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1998년도 Proceedings of UNESCO-internetwork Cooperative Regional Seminar and Workshop on Bioassay Guided Isolation of Bioactive Substances from Natural Products and Microbial Products
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• pp.170-170
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• 1998

In order to discover new types of 5-hydroxytryptamine antagonists, we have devoted our attention to investigating naturally occurring compounds having anti-5HT activity in vitro. Recently, ${\gamma}$-mangostin [1,3,6,7-tetrahydroxy-2,8-bis(3-methyl-2-bytenyl)-9H-xanthen-9-one] from the fruit hull of Garcinia mangostana Linn has been shown to be a selective antagonist for 5-hydroxytryptamine$_{2A}$ receptors in smooth muscle and platelets. It is of interesting that y-mangostin which does not have a nitrogen atom, possesses marked 5-$HT_{2A}$ receptor blocking activity. The present study was undertaken to investigate the effects of ${\gamma}$-mangostin on central 5-HT receptors by using animal behavioural models. Intracerebronventricular injection of ${\gamma}$-mangostin (10-40n mol/mouse) inhibited 5-fluoro-${\alpha}$-methyltryptamin (5-FMT) (45 mg kg$^{-1}$, i.p.)-induced head-twitch response in mice in the presence or absence of citalopram (5-HT-uptake inhibitor). Neither the 5-FMT- nor the 8-hydroxy-2-( di-n-propylamino )tetralin (5-HT$_{1A}$-agonist)-induced 5-HT syndrome (head weaving and hindlimb abduction) was affected by ${\gamma}$-mangostin. The locomotor activity stimulated by 5-FMT through the activation of at-adrenoceptors did not alter in the presence of ${\gamma}$-mangostin. 5-HT-induced inositol phosphates accumulation in mouse brain slices was abolished by ketanserin. ${\gamma}$-Mangostin caused a concentration-dependent inhibition of the inositol phosphates accumulation and the binding of [$^3H$]-spiperone, a specific 5-$HT_{2A}$ receptor antagonist, to mouse brain membranes. Kinetic analysis of the [$^H3$]-spiperone binding revealed that ${\gamma}$-mangostin increased the $_{d}$ value without affecting the $B_{max}$ value, indicating the mode of the competitive nature of the inhibition by ${\gamma}$-mangostin. These results suggest that ${\gamma}$-mangostin inhibits 5-FMT-induced head-twitch response in mice by blocking 5-$HT_{2A}$ receptors not by blocking the release of 5-HT from the central neurone. ${\gamma}$-Mangostin is a promising 5-$HT_{2A}$ receptors antagonist in the central nervous system.m.

• Biomolecules & Therapeutics
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• 제15권3호
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• pp.150-155
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• 2007

In the present study, we have tested the effect of dioleoyl phosphatidic acid (PA) on intracellular $Ca_{2+}$ concentration ($[Ca^{2+}]_{i}$) in two human colon cancer cell lines (HCT116 and HT29). PA and lysophosphatidic acid (LPA), a bioactive lysolipid, increased $[Ca^{2+}]_{i}$ in both HCT116 and HT29 cell lines. Increases of $[Ca^{2+}]_{i}$ by PA and LPA were more robust in HCT116 cells than in HT29 cells. A specific inhibitor of phospholipase C (U73122), however, was not inhibitory to the cell responses. Pertussis toxin, a specific inhibitor of $G_{i/o}$ type G proteins, however, had an inhibitory effect on the responses except for an LPA-induced one in HT29 cells. Ruthenium red, an inhibitor of the ryanodine receptor, was not inhibitory on the responses, however, 2-APB, a specific inhibitor of inositol 1,4,5-trisphosphate receptor, completely inhibited both lipid-induced $Ca^{2+}$ increases in both cell types. Furthermore, by using Ki16425 and VPC32183, two structurally dissimilar specific antagonists for $LPA_{1}/LPA_{3}$ receptors, an involvement of endogenous LPA receptors in the $Ca^{2+}$ responses was observed. Ki16425 completely inhibited the responses but the susceptibility to VPC32183 was different to PA and LPA in the two cell types. Expression levels of five LPA receptors in the HCT116 and HT29 cells were also assessed. Our data support the notion that PA could increase $[Ca^{2+}]_{i}$ in human colon cancer cells, probably via endogenous LPA receptors, G proteins and $IP_{3}$ receptors, thereby suggesting a role of PA as an intercellular lipid mediator.

• Reproductive and Developmental Biology
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• 제28권4호
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• pp.211-219
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• 2004

The effects of adenosine 5'-triphosphate (ATP) and ATP analogs, P/sub 2y/ purinoceptor agonists, on growth of normal mouse mammary epithelial cells (NMuMG) were examined. Cells were plated onto 24 well plates in DMEM supplemented with 10 % fetal calf serum. After serum starvation for 24 hours, ATP, P/sub 2y/ purinoceptor agonists (AdoPP[NH]P, ATP-α-S, ATP-γ-S, β, γ-me-ATP and 2me-S-ATP), P/sub 2u/ purinoceptor agonist (UTP) and P/sub 2y/ purinoceptor antagonists (Reactive Blue 2, more selective to P/sub 2y/ receptor than PPADS; PPADS) were added. DNA synthesis was estimated as incorporation of 3H-thymidine into DNA (1 hour pulse with 1 μ Ci/ml, 18～19 hours after treatment). ATP, Adopp[NH]P, ATP-α-S or ATP-γ-S, significantly increased DNA synthesis at 1, 10 and 100 μM concentrations with dose-dependency (P<0.05), and the maximum responses of ATP and ATP analogs were shown at 100 μM concentration (P<0.05). The potency order of DNA synthesis was ATP≥ATP- γ -S>Adopp [NH]P>ATP-α-S. β, γ -me-ATP, 2me-S-ATP and UTP did not increase DNA synthesis. In autoradiographic analysis of percentage of S-phase cells, similar results were observed to those of DNA synthesis. Addition of 1, 10 or 100 μM Reactive Blue 2 or PPADS significantly decreased ATP (100 μM)-induced DNA synthesis, however, PPADS was less effective than Reactive Blue 2. In Elvax 40P implant experiment, ATP directly stimulated mammary endbud growth in situ suggesting the physiological regulator of ATP in mammary growth. ATP 100 μM rapidly increased MAPK activity, reaching a maximum at 5 min and then gradually decreasing to the base level in 30 min. ATP analogs, Adopp[NH]P and ATP-γ-S also increased MAPK activity, however, β, γ-me-ATP and 2me-S-ATP did not. The inhibitor of the upstream MAPK kinase (MEK), PD 98059 (25 μM), effectively reduced ATP (100 μM) or EGF(10 ng/ml, as positive control)-induced MAPK activity and DNA synthesis (P<0.05). These results indicate that ATP-induced DNA synthesis was prevented from the direct inhibition of MAPK kinase pathway. Overall results support the hypothesis that the stimulatory effects of normal mouse mammary epithelial growth by addition of ATP or ATP analogs are mediated through mammary tissue specific P/sub 2y/ purinoceptor subtype, and MAPK activation is necessary for the ATP-induced cell growth.

• 대한후두음성언어의학회지
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• 제19권2호
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• pp.128-132
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• 2008

Background: Laryngeal contact granuloma is an inflammatory hypertrophic granulation tissue arising at around the vocal process of arytenoid cartilage. Various approaches are currently used for the treatment, but a solid guideline has not been established. Objectives: We aimed to compare the each treatment modality in the hope of suggesting a guideline for the successful management of laryngeal contact granuloma. Method: Eighty-seven treatment cases of 56 patients were analyzed. Cases having recent intubation history were excluded from the study. All patients received vocal hygiene education. Proton pump inhibitors (PPI, N = 33) or H2 receptor antagonists ($H_{2}RA$, N =26) were used as a first-line treatment. Among the non-responders to $H_{2}RA$, 11 cases received PPI as a second-line therapy. Eight cases received botulinum toxin injection and 9 cases had laryngomicrosurgical removal. Results: As an initial therapy, response rate to PPI and $H_{2}RA$ was 60.6% and 38.5% respectively, which was not statistically different (p=0.091). Response rate of PPI as the second-line therapy was 36.3% (p=0.162 when compared to that of first-line PPI therapy). Response rate of Botulinum toxin injection was 75%. All cases of surgical removal recurred in a relatively short period (mean 1.9months). Conclusion: In patients having laryngeal contact granuloma, combined therapy with vocal hygiene education and PPI medication would provide more than 60% of therapeutic response. Botulinum toxin injection is highly effective even in non-responders to antireflux therapy. The only indications of surgery are to resolve diagnostic doubt or to treat acute airway compromise.

• Archives of Pharmacal Research
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• 제16권3호
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• pp.244-250
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• 1993

Calli and suspension cultures were obtained following inoculation of the explant from leaves of Ginkgo biloba L on the supplemented MS basal medium. The obtained calli and suspension cultured cells were able to produce detectable amounts of ginkgolides which are known as natural specific PAF antagonists. The production of ginkgolides in the calli and suspension cultured celles were identified using GC/MS, GC and HPLC with authentic ocmpounds. Since the production of ginkgolides A and B the calli and suspension cultured cells had been confirmed, effects of types and concentration of plant growth regulators, media and illumination on the induction and growth of the callus were studied. The concentrations of growth regulators for optimal callus were studied. The concentrations of growth regulators for optimal callus induction were studied. The concentrations of growth regulators for optimal callus induction were 1.0 to 2.0 mg/L for NAA and o.1 mg/L for kinetin. The growth of the Callus seemed to be more simnultaed with the combination of NAA and kinetin than NAA and BA with illumination at all concentration ranges of 1.0 to 4.0 mg/l for NAA and o.1 to 1.0 mg/L for kinetin or BA studied. Amogn 8 different media used, the induction rate of callus on Anderson, Eriksson, and Shenk and Hildebrant at 4 weeks after the innoculation was almost the same as that of MS. However, callus was rarely induced on Heller or White medium. Suspension cultures were easily initiated with 3 g of callus (fresh weight) derived from ginkgo leaves on supplemented MS medium. A typical growth curve of suspension cultured cells could be obtained by measuring the fresh weight of the suspension cultured cells at every 3 days. To improve the growth of suspension cultured cells of ginkgo, effects of concentrations of NAA, sucrose, phosphate ions and molar ratio of $NH_{4}^+\;to\;NO_{3}^-$ ions in the culture medium were studied. The maximum growth of the cells was achieved when the culture medium contained 1.0 mg/L of NAA, 30 g/L sucrose, 1.75 mM phosphate ions and 1:5 molar ratio of $NH_{4}\;to\;NO_{3}^-$ ions.