• Proceedings of the Korea Water Resources Association Conference
• /
• 한국수자원학회 2005년도 학술발표회 논문집
• /
• pp.464-468
• /
• 2005

산업활동으로 인해 발생하는 슬래그 등의 폐기물을 적절히 처리하는 방법으로서는 저비용 처리형태와 자연계에서 슬래그 등의 특성을 고려한 Filter 기능을 수행할 수 있도록 수질이 악화된 하천이나 정체수역에 투입시켜 수질을 개선시킬 수 있는 방법의 도입이 필요하다. 현재 POSCO에서 발생하는 슬래그와 폐콘크리트의 화학적 성분은 주로 $CaO,\;SiO_2,\;Al_2O_3,\;Fe_2O_3$ 등으로 이루어져 있으며, 침전유발물질 및 흡착성물질이 공존하고 있다. 다공질 형태의 비표면적을 가지고 있어서 정화용 필터로 이용하기에 좋은 이점을 가지고 있다. 슬래그나 폐콘크리트를 Mattress/Filter 채움재 및 수질정화용 여재로 활용하면 폐기물처리, 자원 재활용 그리고 수질 환경 개선의 세 가지 효과를 동시에 얻을 수 있는 방법이 된다. 본 연구에서는 슬래그와 폐콘크리트를 활용한 정체수역에서 정화시스템의 정화특성을 조사하기 위하여 유입수와 유출수의 pH, 용존산소, 질소, 인 등을 측정하여 비교하였다. 수질개선을 위한 Mattress/Filter 시스템의 기본개념은 하천의 오염된 물이 Mattress/Filter의 공극사이를 통과하면서 채움재에 형성된 생물막이 수질 개선과정에서 나타나는 접촉작용, 생물 흡착작용, 생물산화의 분해작용 등을 촉진시키도록 하였다. Mattress/Filter를 이용한 수중 수질개선시스템에서 채움재로 제철폐기물인 슬래그와 건설폐기물인 폐콘크리트를 사용함으로써 Mattress/Filter의 다공성 및 넓은 표면적이라는 특성에 따른 물리적$\cdot$화학적$\cdot$생물학적 작용이 촉진되고 있음을 확인할 수 있었으며, 그 결과 정체수역에 설치한 Mattress/Filter는 다공질 속에서 쉽게 생물막을 형성시키고 유기물의 흡착을 촉진시켜 오염물질을 정화하는데 필요한 자정작용의 효과 증대와 수질개선을 촉진시킬 수 있는 자연생태적 하천정화시스템임을 확인할 수 있었다.

• Biomedical Science Letters
• /
• 제14권2호
• /
• pp.69-76
• /
• 2008

${\gamma}$-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the central nervous system, and its actions are mediated by subtypes of GABA receptors named as $GABA_A$, $GABA_B,\;and\;GABA_C,\;GABA_A$, receptor consisting of ${\alpha},\;{\beta},\;{\gamma}\;and\;{\delta}$ subunits is a heterooligomeric ligand-gated chloride channel. This study was performed to investigate regulation of $GABA_A$ receptor by protein kinase C(PKC). Ion currents were recorded using gramicidine-perforated patch and whole cell patch clamp. mRNA encoding the subunits of PKC expressed in major pelvic ganglion (MPG) neurons was detected by using RT-PCR. The GABA-induced inward current was increased by PKC activators and decreased by PKC inhibitors, respectively. These effects were not associated with intracellular $Ca^{2+}$ and GAG (1-oleoyl-2-acetyl-sn-glycerol), a membrane permeable diacylglycerol (DAG) analogue. These results mean that the subfamily of PKC participating in activation of $GABA_A$ receptor would be an atypical PKC (aPKC). Among theses, ${\xi}$ isoform of aPKC was detected by RT-PCR. Taking together, we suggest that excitable $GABA_A$ receptor in sympathetic MPG neuron seemed to be regulated by aPKC, particular in ${\xi}$ isoform. The regulatory roles of PKC on excitatory $GABA_A$ receptors in sympathetic neurons of MPG may be an important factor to control the functional activity of various pelvic organs such as bowel movement, micturition and erection.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 한국응용약물학회 1996년도 춘계학술대회
• /
• pp.175-175
• /
• 1996

The spinal dorsal horn is the area where primary afferent fibers terminate and cutaneous sensory information is Processed. A number of putative neurotransmitter substances, including excitatory and inhibitory amino acids and peptides, are present in this region and sites and cellular mechanisms of their actions have been a target of numerous studies. In this study, single neurons were acutely isolated and the properties of whole cell current and responses to excitatory and inhibitory neurotransmitters were studied by the patch clamp method. Young rats (7-14 days) were anesthetized with diethyl-ether, and the lumbar spinal cord was excised and cut transversely at a thickness of 30$\mu\textrm{m}$ by Vibroslicer. The treatment of spinal slices with low concentration of proteases (pronase and thermolysin 0.75 mg/$m\ell$) and mechanical dissociation yielded isolated neurons with near intact morphology. Multipolar, ellipsoidal and bipolar, and pyramidal cells were shown. By applying step voltage pulses to neurons held at -70 mV, two types of inward currents and one outward currents observed. The fast activating and inactivating inward current was the Na$\^$+/ current because of its fast kinetics and blocking by 0.5${\mu}$M TTX, a specific blocker of Na$\^$+/ channel. The second type of inward currents were sustained. Based on their kinetics and current-voltage relations, it was likely that the second type of inward current was the voltage-dependent Ca$\^$2+/ current. In the presence of TTX, the steady-state currents mainly represented outward K$\^$+/ current which looked like the delayed rectifier K$\^$+/ current. In addition, the membrane currents produced by agonist of excitatory amino acid (EAA) receptor and the endogenous transmitter candidate L-glutamate were recorded in isolated whole-cell voltage clamped neurons as well as responses to inhibitory amino acids (${\gamma}$-amino butyric acid, glycine). Drugs were applied by a method that allows complete exchange of the solution within 1 sec; an infinite number of solutions can be applied to a single cell.

• The Journal of Pediatrics of Korean Medicine
• /
• 제12권1호
• /
• pp.163-181
• /
• 1998

The purpose of this study was to analyze the Rhizoma on the blood pressure, heart rate and to define the mechanism of Notopterygii Rhizoma-induced relaxation in rabbit common carotid arterial contracted by agonists. Method : In order to explore the effect of Notopterygii Rhizoma on the blood pressure and heart rate, Notopterygii Rhizoma extract was injected in vein of rabbit ear. In order to investigate the effect of Notopterygii Rhizoma on norepinephrine(NE)-induced contracted rabbit carotid arterial strips, transverse strips with intact or damaged endothelium were used for the experiment using organ bath. To analyze the mechanism of Notopterygii Rhizoma-induced relaxation, Notopterygii Rhizoma extract infused into NE-induced contracted strips induced by agonists after treatment of methylene blue, propranolol, ouabain and it infused into serotonin, potassium chloride-induced contracted strips. Result : The blood pressure was significantly decreased by Notopterygii Rhizoma, but heart rate was insignificantly. In addition, Notopterygii Rhizoma significantly relaxed the norepinephrine, serotonin, potassium-induced contracted strips with intact endothelium or damaged endothelium. The relaxing effect of Notopterygii Rhizoma In NE-induced contracted strips with damaged endothelium by pretreatment of methylene blue, propranolol was not changed, but Ouabain was significantly decreased. Conclusion : These results were shown that Notopterygii Rhizoma affected the NE -induced contracted smooth muscle without the participation of endothelium, and demonstrated that the mechanism of NotoDtervgii Rhizoma-induced relaxation was the obstruction of receptor-operated Ca2+ channel.

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권6호
• /
• pp.2559-2563
• /
• 2014

Purpose: We investigated the expression of epithelial $Ca^{2+}$ channel transient receptor potential vanilloid (TRPV) 5 and 6 in non-small-cell lung cancer (NSCLC) and assessed their prognostic role in patients after surgical resection. Materials and Methods: From January 2008 to January 2009, 145 patients who had undergone surgical resection of NSCLCs were enrolled in the study. Patient clinical characteristics were retrospectively reviewed. Fresh tumor samples as well as peritumor tissues were analyzed for TRPV5/6 expression using immune-histochemistry (IHC) and quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). Patients were grouped based on their TRPV5 and TRPV6 levels in the tumor tissues, followed up after surgery, and statistically analyzed to examine the prognostic roles of TRPV5 and TRPV6 on patients' survival after surgical resection of NSCLCs. Results: Using IHC, among the 145 patients who had undergone surgical resection of NSCLCs, strong protein expression (grade${\geq}2$) of TRPV5 and TRPV6 was observed in a lower percentage of primary tumor tissues than in non-tumor tissues of same patients. Similar findigns were obtained with the RT-PCR test for mRNA levels. Decreased overall mRNA levels of TRPV5 and TRPV6 were associated with a worse overall survival rate (p=0.004 and p=0.003 respectively) and shorter recurrence-free survival (p<0.001 and p<0.001 respectively). The combining effect of TRPV5 and TRPV6 on survival was further investigated using multivariate analysis. The results showed that a combination of low expression of TRPV5 and TRPV6 could be an independent predictor of poor recurrence-free survival (p=0.002). Conclusions: Decreased expression of TRPV5/6 in tumor tissues was observed in NSCLC patients and was associated with shorter median survival time after surgical resection. Combined expression of TRPV5 and TRPV6 in tumor tissues demonstrated promising prognostic value in NSCLC patients.

• The Journal of Korean Obstetrics and Gynecology
• /
• 제20권2호
• /
• pp.83-96
• /
• 2007

Purpose: Ligustri Lucidi Fructus and Ecliptae Herba has long been used for clinical therapy associated especially with menopausal symptoms in Korea. To provide a scientific rationale for such use, we have investigated the antioxidant and vasorelaxant effects of Ligustri Lucidi Fructus, Ecliptae Herba and its mixture. Methods: The antioxidant activity of the extracts from Ligustri Lucidi Fructus, Ecliptae Herba and its mixture were evaluated and compared with that of BHA (butylated hydroxyanisole), BHT (butylated hydroxytoluene), vitamin C and vitamin E, using the ${\alpha}$,${\alpha}-diphenyl-{\beta}-picrylhydrazyl$ (DPPH) radical scavenging method. Results: Antioxidant activity of all extracts using the DPPH radical scavenging method decreased in the order vitamin C>BHA>vitamin E>Ligustri Lucidi Fructus>Ligustri Lucidi Fructus:Ecliptae Herba(1:1)>Ecliptae Herba>BHT. The vasorelaxant effects of extracts were investigated on the vasomotor tone of the rat thoracic aorta in an organ bath. All of the extracts elicited along-term relaxing response in the endothelium-intact as well as endothelium-denuded rat aorta contracted with norepinephrine. This relaxant effect was abolished by Precontraction with 72 mM KCI. Thus, it is suggested that the mechanism of vasorelaxant effect of extracts not involve voltage-operated $Ca^{2+}$ channel blocking but receptor-mediated route. Conclusion: These antioxidant and vasorelaxant effecs of the extracts may contribute to the beneficial effects in postmenopausal women.

• Korean Journal of Oriental Medicine
• /
• 제2권1호
• /
• pp.236-254
• /
• 1996

This study was carried out to investigate the tracheal muscle relaxation of water extracts of three kinds of Coptis rhizoma and also compare their effects with berberine and palmatine, which are the important alkaloid components of Coptis rhizoma, in isolated rat tracheal smooth muscle. As a result Coptis chinenis showed significant tracheal muscle relaxation on KCI-induced contraction and more markedly on carbachol-induced contraction in dose-dependent manner. Coptis japoinin exhibited also tracheal muscle relaxation on both contraction with slightly weaker activities than those of Coptis chinensts. The activities of the root hair of Coptis chinensis were the most weakest in three rhizomas. Berberine and palmatine had strong tracheal muscle relaxation, especially, on carbachol-induced contraction, however, their activities on KCI-induced contraction were weaker than that of Coptis chinenis. The inhibitory effects of three kinds of Coptis rhizoma on the contraction by KCI and carbachol were investigated to explain the process of their tracheal muscle relaxation. All rhizomas inhibited the contraction by both agents, among them, Coptis japonica showed the most significant effect, so indicating that the tracheal muscle relaxation of Coptis rhizoma may be concerned with the blocking of muscarine receptor and $Ca^{2+}$channel.

• The Korean Journal of Physiology and Pharmacology
• /
• 제22권5호
• /
• pp.577-584
• /
• 2018

Bladder dysfunction is a common complication of diabetes mellitus (DM). However, there have been a few studies evaluating bladder smooth muscle contraction in DM in the presence of pharmacological inhibitors. In the present study, we compared the contractility of bladder smooth muscle from normal rats and DM rats. Furthermore, we utilized pharmacological inhibitors to delineate the mechanisms underlying bladder muscle differences between normal and DM rats. DM was established in 14 days after using a single injection of streptozotocin (65 mg/kg, intraperitoneal) in Sprague-Dawley rats. Bladder smooth muscle contraction was induced electrically using electrical field stimulation consisting of pulse trains at an amplitude of 40 V and pulse duration of 1 ms at frequencies of 2-10 Hz. In this study, the pharmacological inhibitors atropine (muscarinic receptor antagonist), U73122 (phospholipase C inhibitor), DPCPX (adenosine $A_1$ receptor antagonist), udenafil (PDE5 inhibitor), prazosin (${\alpha}_1$-receptor antagonist), verapamil (calcium channel blocker), and chelerythrine (protein kinase C inhibitor) were used to pretreat bladder smooth muscles. It was found that the contractility of bladder smooth muscles from DM rats was lower than that of normal rats. In addition, there were significant differences in percent change of contractility between normal and DM rats following pretreatment with prazosin, udenafil, verapamil, and U73122. In conclusion, we suggest that the decreased bladder muscle contractility in DM rats was a result of perturbations in $PLC/IP_3$-mediated intracellular $Ca^{2+}$ release and PDE5 activity.

• Biomolecules & Therapeutics
• /
• 제28권4호
• /
• pp.328-336
• /
• 2020

Diabetes mellitus affects the colonic motility developing gastrointestinal symptoms, such as constipation. The aim of the study was to examine the role of intracellular signaling pathways contributing to colonic dysmotility in diabetes mellitus. To generate diabetes mellitus, the rats were injected by a single high dose of streptozotocin (65 mg/kg) intraperitoneally. The proximal colons from both normal and diabetic rats were contracted by applying an electrical field stimulation with pulse voltage of 40 V in amplitude and pulse duration of 1 ms at frequencies of 1, 2, 4, and 6 Hz. The muscle strips from both normal rats and rats with diabetes mellitus were pretreated with different antagonists and inhibitors. Rats with diabetes mellitus had lower motility than the control group. There were significant differences in the percentage of inhibition of contraction between normal rats and rats with diabetes mellitus after the incubation of tetrodotoxin (neuronal blocker), atropine (muscarinic receptor antagonist), prazosin (α₁ adrenergic receptor antagonist), DPCPX (adenosine A1 receptor antagonist), verapamil (L-type Ca²⁺ channel blocker), U73122 (PLC inhibitor), ML-9 (MLCK inhibitor), udenafil (PDE₅ inhibitor), and methylene blue (guanylate cyclase inhibitor). The protein expression of p-MLC and PDE₅ were decreased in the diabetic group compared to the normal group. These results showed that the reduced colonic contractility resulted from the impaired neuronal conduction and decreased muscarinic receptor sensitivity, which resulted in decreased phosphorylation of MLC via MLCK, and cGMP activity through PDE₅.

• Biomolecules & Therapeutics
• /
• 제28권4호
• /
• pp.370-379
• /
• 2020

Econazole, a potent broad-spectrum antifungal agent and a Ca²⁺ channel antagonist, induces cytotoxicity in leukemia cells and is used for the treatment of skin infections. However, little is known about its cytotoxic effects on solid tumor cells. Here, we investigated the molecular mechanism underlying econazole-induced toxicity in vitro and evaluated its regulatory effect on the metastasis of gastric cancer cells. Using the gastric cancer cell lines AGS and SNU1 expressing wild-type p53 we demonstrated that econazole could significantly reduce cell viability and colony-forming (tumorigenesis) ability. Econazole induced G0/G1 phase arrest, promoted apoptosis, and effectively blocked proliferation- and survival-related signal transduction pathways in gastric cancer cells. In addition, econazole inhibited the secretion of matrix metalloproteinase- 2 (MMP-2) and MMP-9, which degrade the extracellular matrix and basement membrane. Econazole also effectively inhibited the metastasis of gastric cancer cells, as confirmed from cell invasion and wound healing assays. The protein level of p53 was significantly elevated after econazole treatment of AGS and SNU1 cells. However, apoptosis was blocked in econazole-treated cells exposed to a p53-specific small-interfering RNA to eliminate p53 expression. These results provide evidence that econazole could be repurposed to induce gastric cancer cell death and inhibit cancer invasion.