• Proceedings of the PSK Conference
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• 2000.04a
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• pp.219.2-219.2
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• 2000

• YAKHAK HOEJI
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• v.45 no.6
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• pp.683-693
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• 2001

This study was attempted to investigate the effect of raclopride, a dopamine $D_2$ receptor antagonist, on renal function in dog. Raclopride (70-220$\mu\textrm{g}$/kg), when given intravenously, Produced antidiuresis along with the decrease in free water clearance ( $C_{H_2O}$), urinary excretion of sodium and potassium ( $E_{Na}$ , $E_{K}$), partially decreased osmolar clearance ( $C_{osm}$) and increased reabsorption rates of sodium and potassium in renal tubules ( $R_{Na}$ , $R_{K}$). Raclopride administered into a renal artery did not influence on renal function in small doses (10 and 30$\mu\textrm{g}$/kg), whereas exhibited the decrease of urine volume (Vol) and $C_{H_2O}$ both in experimental and control kidney in much dose (100$\mu\textrm{g}$/kg), at this time, the decreased rates of both Vol. and $C_{H_2O}$) were more prominent in control kidney rather than that elicited in experimental kidney, and then only via was decreased in control kidney but increased in experimental kidney. Raclopride administered via carotid artery (30-200$\mu\textrm{g}$/kg) did not influence at all on renal function. Antidiuretic action induced by raclopride given intravenously was not affected by renal denervation. Raclopride given into carotid artery was little effect on renal function without relation to renal denervation. Above results suggest that raclopride produces antidiuresis by potentiation of antidiuretic hormone (ADH) action in blood without increase of ADH secretion in posterior pituitary gland, it is not related to renal nerve function in dogs.ogs.s.

• Journal of Microbiology and Biotechnology
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• v.25 no.8
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• pp.1307-1314
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• 2015

Leukemia inhibitory factor (LIF) is a member of the IL-6 cytokine family, having pleiotropic actions such as maintaining stem cell pluripotency and enabling blastocyst implantation. Because the action of LIF is mediated by a ligand-receptor interaction with the LIF receptor (LIF-R), an antagonist for LIF-R has been developed to inhibit LIF-induced signaling. In this study, we present a novel method for the production and purification of an antagonist to human LIF-R (hLA). His-tagged hLA was expressed in E. coli, and simple purification methods without any endopeptidase cleavage were designed. In addition, we determined the optimal temperature conditions for enhancing the production of soluble hLA. Finally, the bioactivity of His-tagged hLA was examined using STAT3 phosphorylation and receptivity of human endometrial ECC-1 cells. Our strategy provides a rapid and efficient method to produce biologically active recombinant hLA.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.1
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• pp.31-39
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• 1998

As it has been reported that the depolarization induced acetylcholine (ACh) release is modulated by activation of presynaptic $A_1$ adenosine heteroreceptor and various lines of evidence suggest the $A_2$ adenosine receptor is present in the hippocampus. The present study was undertaken to delineate the role of adenosine receptors on the hippocampal ACh release. Slices from the rat hippocampus were equilibrated with $[^3H]choline$ and then the release amount of the labelled product, $[^3H]ACh$, which was evoked by electrical stimulation (rectangular pulses, 3 Hz, 2 ms, 24 mA, $5\;V/cm^{-1}$, 2 min), was measured, and the influence of various adenosine receptor-related agents on the evoked tritium outflow was investigated. And also, the drug-receptor binding assay was performed in order to confirm the presence of $A_1$ and $A_2$ adenosine receptors in the rat hippocampus. N-ethylcarboxamidoadenosine (NECA), a potent adenosine receptor agonist with nearly equal affinity at $A_1$ and $A_2$ adenosine receptors, in concentrations ranging from $1{\sim}30\;{\mu}M$, decreased the electrically-evoked $[^3H]ACh$ release in a concentration-dependent manner without affecting the basal rate of release. And the effect of NECA was significantly inhibited by 8-cyclopentyl-1,3-dipropylxanthine (DPCPX, 2 ${\mu}M$), a selective $A_1$ adenosine receptor antagonist, but was not influenced by 3,7-dimethyl-1-propargylxanthine (DMPX, 5 ${\mu}M$), a specific $A_2$ adenosine receptor antagonist. $N^6-cyclopentyladenosine$ (CPA), a selective $A_1$ adenosine receptor agonist, in doses ranging from 0.1 to 10 ${\mu}M$, reduced evoked $[^3H]ACh$ release in a dose-dependent manner without the change of the basal release. And the effect of CPA was significantly inhibited by 2 ${\mu}M$ DPCPX treatment. 2-P-(2-carboxyethyl)-phenethylamino-5'-N-ethylcarboxamidoadenosine hydrochloride (CGS-21680C), a potent $A_2$ adenosine receptor agonist, in concentrations ranging from 0.1 to 10 ${\mu}M$, did not alter the evoked ACh release. In the drug-receptor binding assay, the binding of $[^3H]2-chloro-N^6-cyclopentyladenosine$ ($[^3H]$CCPA) to the $A_1$ adenosine receptor of rat hippocampal membranes was inhibited by CPA ($K_i$ = 1.22 nM), NECA ($K_i=10.17 nM$) and DPCPX ($K_i=161.86 nM$), but not by CGS-21680C ($K_i=2,380 nM$) and DMPX ($K_i=22,367 nM$). However, the specific binding of $[^3H]CGS-21680C$ to the $A_2$ adenosine receptor was not observed. These results suggest that the $A_1$ adenosine heteroreceptor play an important role in evoked ACh release, but the presence of $A_2$ adenosine receptor is not confirmed in this study.

• Bulletin of the Korean Chemical Society
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• v.34 no.2
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• pp.549-552
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• 2013

An efficient and alternative synthesis of enantiomerically pure (+)-(S)-4-(4-((4-chlorophenyl)(pyrid-2-yl)methoxy]piperidin-1-yl)butanoic acid, bepotastine (1) is described. The key resolution of (R/S)-bepotastine l-menthyl ester (3) is achived via diastereomeric salt crystallization using N-benzyloxycarbonyl-L-aspartic acid (NCbzLAA) as the resolving agent to provide (S)-bepotastine l-menthyl ester (S)-3. Hydrolysis of (S)-bepotastine l-menthyl ester (S)-3 afforded the desired bepotastine (1) with good yields and enantiopurity (> 99%). Finally, bepotastine besilate (4) and bepotastine calcium (5) are achived by salt formation of bepotastine (1) with benzene sulfonic acid and calcium salt respectively. The reaction conditions were optimized to make suitable for commercial scale production.

• Journal of Radiation Industry
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• v.7 no.2_3
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• pp.127-134
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• 2013

Bombesin receptors are overexpressed in many kinds of human tumors. In particular, the gastrin releasing peptide receptor (GRPR) which is also called bombesin receptor subtype 2, has been identified in prostate cancer. In the present study, we developed a bombesin antagonist-based $^{177}Lu$-labeled peptide, $^{177}Lu$-DOTA-$Ala(SO_3H)$-Aminooctanoyl-Gln-Trp-Ala-Val-N methyl Gly-His-Statine-Leu-$NH_2$ (DOTA-sBBNA). DOTA-sBBNA was prepared using a solid phase synthesis method. It was labeled with $^{177}Lu$ by a high radiolabeling yield (>98%), and its Log P value was -2.05. The radiolabeled peptide was highly stable in serum incubation at $37^{\circ}C$ for 48 hr. A competitive displacement of $^{125}I-[Tyr^4]$-Bombesin on the PC-3 human prostate carcinoma cells revealed that the $IC_{50}$ value of the peptide was 6.76 nM indicating a highly nanomolar binding affinity for GRPR. These results suggest that $^{177}Lu$-DOTA-sBBNA can be a potential candidate for targeting prostate cancer, and further studies to evaluate its biological characteristics are needed.

• Toxicological Research
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• v.29 no.1
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• pp.21-25
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• 2013

The selective targeting of an integrin ${\alpha}_v{\beta}_3$ receptor using radioligands may enable the assessment of angiogenesis and integrin ${\alpha}_v{\beta}_3$ receptor status in tumors. The aim of this research was to label a peptidomimetic integrin ${\alpha}_v{\beta}_3$ antagonist (PIA) with $^{99m}Tc(CO)_3$ and to test its receptor targeting properties in nude mice bearing receptor-positive tumors. PIA was reacted with tris-succinimidyl aminotriacetate (TSAT) (20 mM) as a PIA per TSAT. The product, PIA-aminodiacetic acid (ADA), was radiolabeled with $[^{99m}Tc(CO)_3(H_2O)_3]^{+1}$, and purified sequentially on a Sep-Pak C-18 cartridge followed by a Sep-Pak QMA anion exchange cartridge. Using gradient C-18 reverse-phase HPLC, the radiochemical purity of $^{99m}Tc(CO)_3$-ADA-PIA (retention time, 10.5 min) was confirmed to be > 95%. Biodistribution analysis was performed in nude mice (n = 5 per time point) bearing receptor-positive M21 human melanoma xenografts. The mice were administered $^{99m}Tc(CO)_3$-ADA-PIA intravenously. The animals were euthanized at 0.33, 1, and 2 hr after injection for the biodistribution study. A separate group of mice were also co-injected with 200 ${\mu}g$ of PIA and euthanized at 1 hr to quantify tumor uptake. $^{99m}Tc(CO)_3$-ADA-PIA was stable in phosphate buffer for 21 hr, but at 3 and 6 hr, 7.9 and 11.5% of the radioactivity was lost as histidine, respectively. In tumor bearing mice, $^{99m}Tc(CO)_3$-ADA-PIA accumulated rapidly in a receptor-positive tumor with a peak uptake at 20 min, and rapid clearance from blood occurring primarily through the hepatobiliary system. At 20 min, the tumor-to-blood ratio was 1.8. At 1 hr, the tumor uptake was 0.47% injected dose (ID)/g, but decreased to 0.12% ID/g when co-injected with an excess amount of PIA, indicating that accumulation was receptor mediated. These results demonstrate successful $^{99m}TC$ labeling of a peptidomimetic integrin antagonist that accumulated in a tumor via receptor-specific binding. However, tumor uptake was very low because of low blood concentrations that likely resulted from rapid uptake of the agent into the hepatobiliary system. This study suggests that for $^{99m}Tc(CO)_3$-ADA-PIA to be useful as a tumor detection agent, it will be necessary to improve receptor binding affinity and increase the hydrophilicity of the product to minimize rapid hepatobiliary uptake.

• Molecules and Cells
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• v.22 no.2
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• pp.198-202
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• 2006

The $P2X_7$ receptor, an ATP-gated cation channel, induces cell death in immune cells and is involved in neurodegenerative diseases. Although the receptor plays various roles in these diseases, the cellular mechanisms involved are poorly understood and antagonists are limited. Here, the development of a cell-based assay for human $P2X_7$ receptor is reported. We established permanent lines of HEK 293 cells expressing a high level of $hP2X_7$ receptor. Functional activity of the $hP2X_7$ receptor was confirmed by whole-cell patch recording of ATP-induced ion currents. Prolonged exposure to ATP resulted in death of the $hP2X_7$-expressing HEK 293 cells and this cell death could be quantified. Two known $P2X_7$ antagonists, PPADS and KN-62, blocked ATP-induced death in a concentration-dependent manner. Thus, this assay can be used to screen for new antagonists of $hP2X_7$ receptors.

• Journal of Acupuncture Research
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• v.23 no.4
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• pp.149-162
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• 2006

Objectives : The aim of this study is to evaluate the analgesic effect of electroacupuncture on Jogsamni (ST36) in the collagen-induced arthritis rats and investigate the role played by opioid receptor subtypes $({\mu},\;{\delta},\;{\kappa})$ in the antinociceptive effect of electroacupuncture (EA) In the thermal hyper algesia test. Methods : Immunization of male Sprague-Dawley rats with bovine type H collagen emulsified in incomplete Freund's adjuvant, followed by booster injection 2 weeks later induced collagen-induced arthritis (CIA). The thermal hyperalgesia was evaluated weekly with tail flick latency (TFL). In the fourth week after first immunization, EA stimulation (2 Hz, 0.07 mA, 0.3 ms) was delivered into Jogsamni (5736) for 20 minutes. Analgesic effect was evaluated by using the tail flick latency (TFL) after intraperitoneal injection of normal saline, naloxone, naltrindole and nor-binaltorphimine respectively to CIA rats. Results : The results were as follows; 1. The TFL were gradually decreased in CIA as time elapsed after e immunization of arthrogenic collagen and the maximum value was reached between the third to fifth week. 2. EA stimulation on 5736 inhibited chronic inflammatory pain induced by CIA. 3. The analgesic effect of EA was inhibited by pretreatment of ${\mu}-receptor$ antagonist (naloxone),${\delta}-receptor$ antagonist (naltrindole) and ${\kappa}-receptor$ antagonist (nor-binaltorphimine) respectively. Conclusion : Electroacupuncture has an analgesic effect on the CIA rat and has an antinociception mediated by 8, 5, H receptors.

• Clinical and Experimental Reproductive Medicine
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• v.30 no.4
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• pp.269-280
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• 2003

Objective: We reported the overcoming effect of $Ni^{2+}$ on the in vitro 2-cell block of mouse embryos. In this study, we aim to investigate whether $Ni^{2+}$ should induce intracellular $Ca^{2+}$ transient in the mouse embryos. Materials and Methods: Embryos were collected at post hCG 32hr from the oviduct of the ICR mouse and cultured in M2 medium omitted phenol red. Intracellular $Ca^{2+}$ was checked by using a confocal laser scanning microscope and fluo-3AM by using various intracellular $Ca^{2+}$ antagonists. Results: In 1mM $Ni^{2+}$ treated medium which contained $Ca^{2+}$(1.71mM), 75.7% of the embryos showed $[Ca^{2+}]i$ transient about 200 sec later. In the $Ca^{2+}$-free medium, 69.8% of the embryos showed $[Ca^{2+}]i$ transient. In U73122, phospholipaseC(PLC) inhibitor (5uM, 10min) pretreated group, 33.3% of the embryos showed $[Ca^{2+}]i$ transient. Heparine, inositol 1, 4, 5-triphosphate receptor(IP3R) antagonist preinjected embryos showed no response with 1mM $Ni^{2+}$. In danthrolene treatment, ryanodine receptor(RyR)-antagonist, 43% embryos showed $[Ca^{2+}]i$ transient but they showed delayed response about 340sec in the presence of $Ca^{2+}$. Conclusions: Summing up the above results, $Ni^{2+}$ seems to induce $Ca^{2+}$-release from the $Ca^{2+}$-store even in the $Ca^{2+}$-free medium. IP3 receptors of the mouse 2-cell embryos might have an essential role for the intracellular $Ca^{2+}$ increase by $Ni^{2+}$.