• Title/Summary/Keyword: inhibitor injection

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The Inhibitory Mechanism on Acetylcholine-Induced Contraction of Bladder Smooth Muscle in the Streptozotocin-Induced Diabetic Rat

  • Han, Jong Soo;Kim, Su Jin;Nam, Yoonjin;Lee, Hak Yeong;Kim, Geon Min;Kim, Dong Min;Sohn, Uy Dong
    • Biomolecules & Therapeutics
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    • v.27 no.1
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    • pp.101-106
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    • 2019
  • Most diabetic patients experience diabetic mellitus (DM) urinary bladder dysfunction. A number of studies evaluate bladder smooth muscle contraction in DM. In this study, we evaluated the change of bladder smooth muscle contraction between normal rats and DM rats. Furthermore, we used pharmacological inhibitors to determine the differences in the signaling pathways between normal and DM rats. Rats in the DM group received an intraperitoneal injection of 65 mg/kg streptozotocin and measured blood glucose level after 14 days to confirm DM. Bladder smooth muscle contraction was induced using acetylcholine (ACh, $10^{-4}M$). The materials such as, atropine (a muscarinic receptor antagonist), U73122 (a phospholipase C inhibitor), DPCPX (an adenosine $A_1$ receptor antagonist), udenafil (a PDE5 inhibitor), prazosin (an ${\alpha}_1$-receptor antagonist), papaverine (a smooth muscle relaxant), verapamil (a calcium channel blocker), and chelerythrine (a protein kinase C inhibitor) were pre-treated in bladder smooth muscle. We found that the DM rats had lower bladder smooth muscle contractility than normal rats. When prazosin, udenafil, verapamil, and U73122 were pre-treated, there were significant differences between normal and DM rats. Taken together, it was concluded that the change of intracellular $Ca^{2+}$ release mediated by PLC/IP3 and PDE5 activity were responsible for decreased bladder smooth muscle contractility in DM rats.

A Cytogenetic Study on Induction of Diploid Spermatozoa in Poultry (가금류 정자 세포의 배수성 유기를 위한 세포 유전학적 연구)

  • 김철욱;손시환;전익수
    • Korean Journal of Poultry Science
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    • v.23 no.1
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    • pp.1-7
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    • 1996
  • In order to produce polyploid quail, the patterns of spermatogenesis and induction of diploid spermatozoa were analyzed by administration of spindle fiber inhibitor agent. Colcemid at the dose level of 37 $\mu\textrm{g}$ /100 g BW was Injected intraperitoneally to 50 Japanese quail males for 3 consecutive days. Five to 20 days after the first colcemid injection, the metaphase spreads from mitotic spermatogonia, primary spermatocyte and secondary spermatocyte were observed. By cytogenetic analysis, 9.4% of spermatogonia and spermatocyte cells in germ cells from the treated males was found to be polyploid cells. As compared with colcemld treated, the males with non-treated colcemid had only 2.3% polyploid cells in germ cells. The induction of diploid germ cells was highest in 10 days after the first colcemid injection and was lowest in 5 days after the first colcemid injection. These results suggested that between 10 to 15 days before maturation of the spermatozoa, the male germ cells were most sensitive to colcemid treatment. Spindle fiber inhibitor agent was also more sensitive to mitotic division of spermatogonia than meiotic division of primary and secondary spermatocyte.

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Radio-Iodinated arbutin for tumor imaging

  • Huynh, Phuong Tu;Ha, Yeong Su;Lee, Woonghee;Yoo, Jeongsoo
    • Journal of Radiopharmaceuticals and Molecular Probes
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    • v.3 no.2
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    • pp.72-79
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    • 2017
  • Arbutin is a hydroquinone derivative with a glucose moiety. As a tyrosinase inhibitor, it is widely used as a skin-whitening cosmetic agent for the treatment of cutaneous hyperpigmentary disorders, such as melasma and freckles. In the medical field, many studies have addressed the use of arbutin in various tumors, but the mechanism for tumor uptake of arbutin is still unclear. In this paper, we radiolabeled arbutin using radioiodine and studied its pharmacokinetics and tumor uptake via biodistribution experiments and single-photon emission computed tomography (SPECT) imaging. Radiolabeled $^{131}I-arbutin$ was stable for up to 24 h in PBS and serum. Biodistribution studies and SPECT imaging indicated high uptake of the compound in the bladder and kidneys shortly after injection. Twenty-four hours post-injection, significant deiodination was observed. Apart from high thyroid uptake, selective tumor uptake was clearly observed. The tumor-to-muscle and tumor-to-blood ratios were 26 and 9, respectively.

The Involvement of Protein kinase C in Glutamate-Mediated Nociceptive Response at the Spinal Cord of Rats (흰쥐의 척수에서 Glutamate가 매개하는 Nociceptive Response에 있어서 Protein kinase C의 관련성)

  • 김성정;박전희;이영욱;양성준;이종은;이병천;손의동;허인회
    • YAKHAK HOEJI
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    • v.43 no.2
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    • pp.263-273
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    • 1999
  • When glutamate was infected intrathecally, the result is similar to those produced by TPA injected. The involvement of protein kinase C (PKC) in the nociceptive responses in rat dorsal horn neurons of lumbar spinal cord was studied. In test with formalin, a PKC inhibitor (chelerythrine) inhibited dose-dependently the formalin-induced behavior response. Neomycin also inhibited it significantly. But, a PKC activator (12-O-tetradecanoylphorbol-13-ester, TPA) showed reverse effect. When gluatamate was injected intrathecally, we observed the result is smilar to those produced by TPA injection. On the other hand, intrathecal injection of glutamate induced thermal and mechanical hyperalgesia. In Tail-flick test, we examined the involvement of PKC on the glutamate-indeced thermal hyperalgesia. Chelerythrine showed an inhibitory effect and TPA enhanced thermal response. Glutamate decreased the mechanical threshold significantly. A pretreatment of chelerythrine and neomycin inhibited glutamate-induced mechanical hyperalgesia, but the effect of neomycin was not significant. TPA had little effect on the mechanical nociceptive response. These results suggest that the PKC activation through metabotropic receptor at postsynaptic region of spinal cord dorsal horn neurons may influence on the persistent nociception produced by chemical stimulation with formalin, thermal and mechanical hyperalgesia induced by glutamate.

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Preparation and Evaluation of $PGE_1$ Urethral Suppositories ($PGE_1$ 요도좌제의 제조 및 평가)

  • Park Somin;Choi Myeongsin;Han Kyuwon;Kim Kil-Soo
    • YAKHAK HOEJI
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    • v.49 no.4
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    • pp.260-267
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    • 2005
  • [ $PGE_1$ ] is an endogenous substance of potent vasodialator as well as inhibitor of platelet aggregation. It has been used therapeutically in peripheral arterial occlusive disease and impotence. Intracavernous injection of $PGE_1$ for erectile dysfunction has been established for several years as a treatment option for erectile dysfunction of diverse etiologies, but this mode of administration is limited by penile discomfort, pain at the injection site, inconvenience and noncompliance. As the matter of worse, the $\beta-hydroxy$ moiety of $PGE_1$ is extremely susceptible to dehydration in solution to give inactive $PGA_1$ and $PGB_1$. For the improvement of stability, rapid absorption at action site and the convenience of application, $PGE_1$ was formulated as urethral suppositories of three types of formulations, such as PEG, witepsol, and the mixture of PEG and witepsol. The stability test of $PGE_1$ and the release test in urinary suppositories were performed. Futhermore, the effect of enhancers and vehicle composition on the penetration of $PGE_1$ through excised rat skin was evaluated by permeability coefficient and enhancement ratio.

Stimulatory Effect of Ginseng Saponin on Endogenous Production of Nitic Oxide

  • Kim, Hye-Young
    • Proceedings of the Ginseng society Conference
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    • 1998.06a
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    • pp.199-207
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    • 1998
  • Ginseng saponin (G5) purified from Panax ginseng, increase renal blood flow in rats. Nitric oxide (NO) is thought to be a substance endogenously released by G5 in preconstricted lungs and cultured endothelial cells. The present study aims to determine whether G5 could stimulate endogenous 1'elease of NO in rat kidney and urine levels of the stable NO metabolites, nitrite (NO,) and nitrate (NO,) and urinary COMP levels were measured 8 hr after a single intraperitoneal injection of GS (200 mg/kg) Into rats. The effects of the WO synthesis inhibitor, Nu-nitro-L-arginine methyl ester, .1nd the NO precursor, L-arginine, on the G5-induced changes were also determined. The activity of NO synthase, as determined by conversion of ('"C)-L-arginine to ('"C)-L-citrulline, in whole kidney, glomeruli and cortical tubules were also investigated. A single injection of GS resulted in endogenous production of NO as reflected by increase in serum and urine levels of N021N03 and urinary cGMP levels, which were inhibited by the addition o ( N-nitro-L-arginine methyl ester and restored fly L-arginine. GS also stimulated the activity of NO synthase in whole kidney as well as glomeruli and cortical tubules, and Nu-nitro-L-arginine methyl tilter significantly prevented this increase. In conclusion, GS stimulates endogenous NO production and thus, may play a protective role 1 11 the kidney by modulating renal blood flow.

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The number of primitive endoderm cells in the inner cell mass is regulated by platelet-derived growth factor signaling in porcine preimplantation embryos

  • Jong-Nam Oh;Mingyun Lee;Gyung Cheol Choe;Dong-Kyung Lee;Kwang-Hwan Choi;Seung-Hun Kim;Jinsol Jeong;Chang-Kyu Lee
    • Animal Bioscience
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    • v.36 no.8
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    • pp.1180-1189
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    • 2023
  • Objective: Discovering the mechanism of cell specification is important to manipulate cellular lineages. To obtain lineage-specific cell lines, the target lineage needs to be promoted, and counterpart lineages should be suppressed. Embryos in the early blastocyst stage possess two different cell populations, the inner cell mass (ICM) and trophectoderm. Then, cells in the ICM segregate into epiblasts (Epi) and primitive endoderm (PrE). PrE cells in embryos show specific expression of platelet-derived growth factor (PDGF) and its receptor, PDGF receptor A (PDGFRA). In this study, we suppressed PDGF signaling using two methods (CRISPR/Cas9 injection and inhibitor treatment) to provide insight into the segregation of embryonic lineages. Methods: CRISPR/Cas9 RNAs were injected into parthenogenetically activated and in vitro fertilized embryos. The PDGF receptor inhibitor AG1296 was treated at 0, 5, 10, and 20 µM concentration. The developmental competence of the embryos and the number of cells expressing marker proteins (SOX2 for ICM and SOX17 for PrE) were measured after the treatments. The expression levels of the marker genes with the inhibitor were examined during embryo development. Results: Microinjection targeting the PDGF receptor (PDGFR) A reduced the number of SOX17-positive cell populations in a subset of day 7 blastocysts (n = 9/12). However, microinjection accompanied diminution of Epi cells in the blastocyst. The PDGF receptor inhibitor AG1296 (5 µM) suppressed SOX17-positive cells without reducing SOX2-positive cells in both parthenogenetic activated and in vitro fertilized embryos. Within the transcriptional target of PDGF signaling, the inhibitor significantly upregulated the Txnip gene in embryos. Conclusion: We identified that PDGF signaling is important to sustain the PrE population in porcine blastocysts. Additionally, treatment with inhibitors was a better method to suppress PrE cells than CRISPR/Cas9 microinjection of anti-PDGF receptor α gene, because microinjection suppressed number of Epi cells. The PDGF receptor might control the number of PrE cells by repressing the proapoptotic gene Txnip. Our results can help to isolate Epi-specific cell lines from blastocysts.

The effect of indomethacin on the protamine induced hemodynamic changes (Protamin 투여로 야기되는 혈역학적 변화에 미치는 Indomethacin 의 영향)

  • Kim, Gyeong-U;Jo, Geon-Hyeon;Lee, Hong-Gyun
    • Journal of Chest Surgery
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    • v.23 no.2
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    • pp.222-230
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    • 1990
  • Protamine, a polycationic peptide extracted from fish, has been widely used for the reversal of anticoagulant action of heparin. However it may cause untoward circulatory side effects including hypotension and bradyarrhythmia. Nowadays, histamine and prostacyclin are regarded as one of the causative agents in the underlying mechanism of hemodynamic changes. To certify the possible role of histamine and prostacyclin, we observed simultaneous changes of the hemodynamic status, plasma concentration of thromboxane B, and circulating platelet count before and after intravenous injection of protamine. Experimental dogs, weighing 12-14kg, were divided into 2 groups; group A animals [n=10], were pretreated with indomethacin[2.5mg/kg] and group B animals[n=10] were pretreated with chlorpheniramine[0.5mg/kg] Heparin[3mg/kg] and protamine [3mg/kg] were administered sequentially in both groups. The results were as follows ; 1. The mean systemic arterial pressure was maintained well in groups A, whereas in group B it decreased from 165\ulcorner18mmHg to 138\ulcorner30mmHg[p<0.01] and 151\ulcorner21 mmHg[p<0.05] at 1 minute and 2 minutes after protamine injection. The mean pulmonary arterial pressure was not changed significantly in group A, whereas in group B it increased from 852 mmHg to 11\ulcorner3 mmHg[p<0.05], 11\ulcorner3 mmHg[p<0.05] and 10\ulcorner3 mmHg[p<0.05] at 1 minute, 3 minutes and 5 minutes after protamine injection. 2 The thromboxane B2 was not changed significantly in group A, whereas in group B it increased from 399\ulcorner401 \ulcornerg/ml to 744\ulcorner615 \ulcornerg/ml[p<0.05] and 814\ulcorner1070 \ulcornerg/ml [p<0.0 5] at 1 minute and 3 minutes after protamine injection without concomitant changes of pulmonary vascular resistance and pulmonary capillary wedge pressure. 3. The number of circulating platelet was not changed in group A, whereas in group B it decreased from 207100\ulcorner103600/\ulcornerl to 159700\ulcorner90900/\ulcornerl [p<0.05] at 1 minute after protamine injection, Although thromboxane B2 and platelet count were changed significantly after protamine injection, they did not cause the remarkable hemodynamic changes. Considering the above results, hemodynamic changes may be caused mainly by prostacyclin rather than thromboxane or platelet. Therefore, the pretreatment with cyclooxygenase inhibitor would be beneficial to prevent circulatory adverse effects of protamine for the patients undergoing cardiac surgery.

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In Vivo Tumor Cell Distribution of Antibody-Endostatin Fusion Protein for Tumor-Specific Targeting and Pharmacokinetics (암세포 표적지향화를 위한 항체-엔도스타틴 융합단백질의 체내동태 및 종양으로의 이행성)

  • Kang, Young-Sook;Lee, Na-Young
    • Journal of Pharmaceutical Investigation
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    • v.33 no.4
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    • pp.287-292
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    • 2003
  • A novel antitumor agent, antibody-endostatin fusion protein $(anti-HER2/neu\;IgG3C_H3-Endostatin,\;AEFP)$ formed by genetic engineering procedure from antibody (Ab) which specifically targets to tumor cells ad angiogenesis inhibitor, endostatin (Endo) that has excellent antitumor effect, minimizes the toxicity of normal cells and selectively kills only tumor cells. The purpose of this study is to evaluate the phamacokinetic parameters and to analyze the localization of AEFP. After an intravenous injection of $150\;{\mu}l\;(5\;{\mu}Ci)\;[^{125}I]Ab,\;[^{125}I]AEFP$ to mice, blood was collected though retroorbital plexus from 15 min to 2880 min. Following the jugular vein injetion of $150\;{\mu}l\;(10\;{\mu}Ci)\;[^{125}I]Endo$, blood was collected by the use of carotid artery cannulation from 0.25 min to 30 min. Consequently, Endo was very rapidly removed from plasma compartment within 30 min. On the other hand, AEFP similar to Ab was slowly cleared from plasma. Also, Endo was metabolized about 40% within 30 min. However, AEFP was shown to metabolize less than 10% within 2880 min. The organ distribution of Endo was in order kidney, lung, spleen. Both Ab and AEFP were localized in order spleen, kidney, liver. Futhermore the tumor/blood distribution ratio of AEFP at 96 hours after injection is about 20 times higher than it of Endo at one hour after injection. In conclusion, these studies demonstrate that the anti-cancer or suppression of angiogenesis effect of Endo may be improved by the use of AEFP because the longer half life and stability of AEFP is able to selectively target antigens expressed on tumors.

Effects of L-NAME on the Mechanical Hyperalgesia after the Development of Inflammation by Freund's Complete Adjuvant in Rat Paw (FCA에 의한 염증 유발 후 주입된 L-NAME이 기계적 통각과민에 미치는 영향)

  • Kim, Min-Kyung;Choi, Yoon;Kong, Hyun-Seok;Leem, Joong-Woo;Leem, Hang-Soo;Chung, Soo-Jin;Lee, Cheong
    • The Korean Journal of Pain
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    • v.12 no.2
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    • pp.171-176
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    • 1999
  • Background: Effect of nitric oxide on the hyperalgesia induced by inflammation is controversial. From our previous experiment, NOS inhibitor, L-NAME given during the induction period decrease mechanical hyperalgesia occured by Freund's complete adjuvant induced inflammation. In addition, we attempted to analyze the effects of L-NAME on mechanical hyperalgesia after the development of inflammation by Freund's complete adjuvant in rat paw. Methods: Male Sprague Dawley rats were divided into four groups; control (normal saline), and three different doses of L-NAME (0.1 mg, 1 mg, 10 mg). Inflammation was induced in rats by injecting 0.15 ml of Freund's complete adjuvant (FCA) intraplantarly. Rats showed typical hyperalgesia within twelve hours after injection and maintained this for about one week. Tests were done 2 days after injection of FCA. After the baseline test either L-NAME or saline was injected under light halothane anesthesia. Effect of L-NAME on hyperalgesia was assessed by measuring mechanical hyperalgesia at 15, 30, 60, 90, 120 minutes. Same experients were repeated on normal rats. Results: When injected at the site of inflammation, L-NAME caused dose dependent decrease in mechanical hyperalgesia. However, normal rats also showed increased mechanical threshold after L- NAME injection. Conclusions: Although L-NAME reduces FCA induced mechanical hyperalgesia, this result may solely be due to inhibition of nitric oxide production and need to be further determined.

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