• Title/Summary/Keyword: brain uptake

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The Eye/Brain Radioactivity Ratio for Assessment of Graves' Ophthalmopathy (Graves병 안구증에서 $^{99m}Tc-DTPA$ 뇌신티그라피를 이용한 안구/뇌 방사능비에 관한 연구)

  • Lee, B.W.;Sung, S.K.;Park, W.;Suh, K.S.;Choi, D.J.;Kim, J.S.
    • The Korean Journal of Nuclear Medicine
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    • v.22 no.1
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    • pp.27-31
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    • 1988
  • In Graves' disease, changes in orbital tissue and structure are casued by inflammatory infiltation, which induces increase of capillary permeability and breakdown of blood-tissue barriers. Using the uptake of $^{99m}Tc-DTPA$ in inflammatory lesion, Eye/Brain radioactivity ratios in brain scintigraphy were evaluated in 15 normal controls and 40 Graves' patients. The results were as follows; 1) Eye/Brain radioactivity ratio was significantly higher in Graves' ophthalmopthy group than in control group (p < 0.005). 2) In Graves' ophthalmopathy, Eye/Brain radioactivity ratio was significantly higher in active (progressive) group than in inactive (non-progressive) group (p < 0.05). 3) There was no correlation between class of ATA classification of Graves' ophthalmopathy and Eye/Brain radioactivity ratio. 4) There was no correlation between Eye/Brain radioactivity ratio and serum activity of TBII. In conclusion, Eye/Brain radioactivity ratio using $^{99m}Tc-DTPA$ brain scintigraphy may be useful to determine the activity of Graves' ophthalmopathy and whether treatment of Graves' ophthalmopathy is necessary or not.

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Brain uptake through the blood-brain barrier, pharmacokinetics and analgesic effect of [$^3$H]Oxytocin in the rat

  • Park, Ji-Hyun;Kang, Young-Sook
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1998.11a
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    • pp.152-153
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    • 1998
  • Oxytocin (OT) is a neurohypophyseal nonapeptide which plays an important role in CNS function as well as uterine contraction during delivery. Furthermore, recently it has been reported that OT may also have analgesic effect and found that the release of OT is related with opioid receptors, especially $\kappa$ and ${\mu}$.

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Functional Characterization and Regional Expression of Dopamine Transporter (도파민 수송체의 기능적 특성 및 발현에 관한 연구)

  • 이상훈;이송득;성기욱;이동섭;이용성;고재경
    • YAKHAK HOEJI
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    • v.39 no.2
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    • pp.161-168
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    • 1995
  • Brain dopamine systems play a central role in the control of movement, hormone release, and many complex behavior. The action of dopamine at its synapse is terminated predominately by high affinity reuptake into presynaptic terminals by dopamine transporter (DAT). The dopamine transporter(DAT) is membrane protein localized to dopamine-containing nerve terminals and closely related with cocaine abuse, Parkinsonism, and schizophrenia. In present study, the recombinant plasmid pRc/CMV-DAT, constructed by subcloning of a cDNA encoding a bovine DAT into eukaryotic expression vector pRc/CMV, was stably transfected into CV-1 cells(monkey kidney cell line). The DAT activities in the cell lines selected by Geneticin$^{R}$ were determined by measuring the uptake of $[^3H]$-dopamine. The transfected cell lines showed 30-50 fold higher activities than untransfected CV-1 cell line, and this result implies that DAT is well expressed and localized in transfected cells. The transfected cells accumulated $[^3H]$-dopamine in a dose-dependent manner with a $K_{m}$ of 991.6nM. Even though high doses of norepinephrine, epinephrine, serotonin, and choline neurotransmitters inhibited the uptake of $[^3H]$-dopamine, DAT in transfected cell line was proven to be much more specific to dopamine. The psychotropic drugs such as GBR12909, CFT, normifensine, clomipramine, desipramine, and imipramine inhibited significantly the dopamine uptake in tissue culture cells stably transfected with DAT cDNA. Radioactive in situ hybridization was done to map the cellular localization of DAT mRNA-containing cells in the adult rat central nervous system. The strong hybridization signals were detected only in the substantia nigra pars compacta and ventral tegmental area. The restricted anatomical localization of DAT mRNA-containing cells confirms the DAT as a presynaptic marker of dopamine-containing cells in the rat brain.

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EFFECTS OF ACUTE AND SUBACUTE ADMINISTRATION OF COCAINE ON DOPAMINERGIC SYSTEMS IN THE RAT STRIATUM

  • Lim, D.K.;Ho, I.K.
    • Toxicological Research
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    • v.6 no.1
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    • pp.75-88
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    • 1990
  • The characteristics of dopamine uptake, D-1 and D-2 receptors after acute and subacute cocaine administration were determind in striatum from WKY and SHR. Cocaine was administered either acutely (40 mg/kg, s.c.) or twice daily (20 mg/kg, s.c.) for 3 and 7 days in 9-wk old WKY and SHR. Rats were sacrificed 30 min, 2 or 24 h after the single injection and 18 h after the last administration to the subacutely treated group. The changes in dopamine uptake, dopamine uptake sites, D-1 and D-2 receptors were determined using $(^3H)$dopamine, $(^3H)$-GBR-12935, $(^3H)$SCH-23390 and $(^3H)$sulpiride, respectively. In acutely treated rats, significant increases in $V_{max}$of dopamine uptake were observed 30 min after the cocanine injection in both strains without changes in $K_m$ values. The in vitro $IC_{50}$for cocaine was significantly decreased 30 min in WKY and 2 h in SHR. However, that for in vitro GBR-12909 was significantly increased 30 min and 2 h in both strains. Also densities of $(^3H)$-GBR-12935 binding sites were significantly increased 30 min and 2 h without changes in their $K_d$. Significant increases in D-2 receptor density were observed 30 min, 2 or 24 h after acute injection in both strains without changes in their affinities. The density of D-1 receptor was significantly decreased 30 min after the injection in WKY, but not in SHR. In subacutely treated rats, a significant increase in $K_m$ of dopamine uptake was observed in 7-day treated SHR. The in vitro $IC_{50}$fot GBR-12909 was significantly increased in 3-day treated WKY. The density of D-1 receptors was significantly increased in 3- and 7-day treated WKY, but not in SHR. The affinity of both binding sites remained unchanged. The results suggest that cocanine administration alters dopamine uptake, characteristics of dopamine uptake sites and dopamine receptor binding characteristics in rat brain. Furthermore, D-1 and D-2 dopamine receptors appear to be differently regulated.

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LOW PERMEABILITY THROUGH THE BLOOD-BRAIN BARRIER OF MORPHINE GLUCURONIDES.

  • Kang, Young-Sook;Ulrich Bickel;Oliver P. Schumacher;Karlheinz Voigt
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1996.04a
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    • pp.246-246
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    • 1996
  • The glucuronide conjugates of morphine have been claimed to exert significant neuropharmacological effects. Morphine-6-glucuronide (M6G) may be a potent opioid agonist in vivo, and morphine-3-glucuronide (M3G) may act as a weak opioid antagonist. The present study addressed the permeability of the blood-brain barrier (BBB) for these metabolites compared to morphine. Tracers were prepared by enzymatic glucuronidation of U-methyl-$^3$H]-morphine. Brain uptake in rats was measured by the internal carotid artery perfusion technique and after i.v. bolus injections. In the perfusion experiments morphine showed a permeability-surface area product (PS) of 3.52${\pm}$0.61 ${\mu}$L min$\^$-1/ g$\^$-1/ Uptake seems to be mediated by passive diffusion and was not saturable by 100 ${\mu}$M morphine in the perfusate. The BBB permeability of [$^3$H]-M3G and [$^3$H]-M6G was too low to be quantified after 5 min of perfusion. Brain uptake of [$^3$H]-M3G and [$^3$H]-M6G 60 min after i.v. bolus injection reached 0.0060${\pm}$0.0003 and 0.0030${\pm}$0.0005% injected dose per g, respectively. From these brain concentrations and from the corresponding plasma concentration - time curves, BBB PS values of 0.14${\pm}$ 0.02 ${\mu}$L min$\^$-1/g$\^$-1/ and 0.11 ${\pm}$ 0.01 ${\mu}$L min$\^$-1/g$\^$-1/, respectively, were calculated. The ratio of BBB PS values is complementary to the analgesic potencies of morphine and M6G after different routes of administration. The low PS of MSG explains, why it is approximate]y equipotent to morphine after systemic injection, although it is about 2 orders of magnitude more potent than morphine after administration directly into the central nervous system.

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Aluminium increase Iron uptake into Glial cells

  • Cheong, Jae-Hoon;Lim, Sung-Sup;Lee, Choong-Jae
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.293.3-294
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    • 2002
  • In the brain, glial cells serve in the role to sequester metal from the neural microenvironment and therefore play an important role as a cellular deposition site. The central nervous system is highly vulnerable to oxidative stress, and free iron can stimulate oxidative stress by the Fenton reaction. Aluminum may upregulates the transferrin-independent iron uptake system and stimulate oxidative stress. Nramp2. also known as DMT 1. is a 12-transmembrane(TM) domain protein responsible for dietary iron uptake as well as metal ions such as iron. lead, mangamese. zinc. copper, and cobait. (omitted)

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The changes of cerebral blood flow by brain imaging algorithm in the Normal Brains : Analysis by Statistical Parametric Mapping (정상 뇌혈류 영상에서 재구성 알고리즘 적용에 따른 섭취율 차이 : 통계적 파라미터 지도를 사용한 분석)

  • Lee, Hyo-Yeong;Kim, Yun-Jin;Sin, Sung-Gyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.11
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    • pp.5311-5316
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    • 2012
  • Single Photon Emission Computed tomography(SPECT) was performed on 13 healthy adults (average age: 39) to investigate the changes of cerebral blood flow according to brain imaging analysis algorithm. The acquired images were filtered and reconstructed through Filtered Back Projection (FBP) and Ordered Subset Expectation Maximization (OSEM). The brain distribution data of radiopharmaceuticals were compared using Statistical Parametric Mapping (SPM), and the changes of blood flow was expressed in Cluster. As a result, uptake rate was increased in Sub-gyral, Sub-Lobar, Extra-Nuclear, Limbic lobe and Cingulate Gyrus, while uptake rate was decreased in Middle frontal gyrus, Inferior Frontal Gyrus and Precentral Gyrus. The discriminable SPM was shown according to cerebral blood flows in Cluster by the reconstruction algorithm.

Brain Abscess Uptake at TI-201 Brain SPECT (탈륨-201 SPECT에서 뇌농양 집적)

  • Lee, Won-Hyoung;Han, Eun-Ji;Yoo, le-Ryung;Chung, Yong-An;Sohn, Hyung-Sun;Kim, Sung-Hoon;Chung, Soo-Kyo;Choi, Yeong-Jin
    • Nuclear Medicine and Molecular Imaging
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    • v.41 no.4
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    • pp.339-341
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    • 2007
  • A 22-year-old woman with a history of acute lymphoblastic leukemia was hospitalized for headache and vomiting. CT scan showed a well-defined, ring like enhancing mass in the left frontal lobe with surrounding edema and midline shift. Magnetic resonance imaging demonstrated a round homogeneous mass with a ring of enhancement in the left frontal lobe. Tl-201 brain SPECT showed increased focal uptake coinciding with the CT and MRI abnormality. Aspiration of the lesion performed through a burr hole yielded many neutrophils, a few lymphocytes and histiocytes with some strands of filamentous microorganism-like material. Modified AFB stained negative for norcardia. Gram stain showed a few white blood cells and no microorganism. Antibiotics were started and produced a good clinical response. After one month, CT scan showed markedly reduction in size and extent was observed.

The Blood-Brain Barrier Permeability and Pharmacokinetics of Nitrone Based Spin Trapping Agent, $\alpha$-Phenyl-n-tert-Butyl Nitrone (PBN) in Rats (흰쥐에서 nitrone계 항산화제인 $\alpha$-phenyl-n-tert-butyl nitrone(PBN)의 뇌 투과성 및 체내동태)

  • 이나영;강영숙
    • YAKHAK HOEJI
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    • v.46 no.2
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    • pp.124-128
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    • 2002
  • The nitrone-based free radical trapping reagent, $\alpha$-phenyl-n-tert-butyl nitrone (PBN) has been proposed as therapeutic agent for stroke. We used this for model drug of development of new drug for neuroprotection. The purpose of this study was to evaluate the blood-brain barrier (BBB) permeability of PBN in Sprague-Dawly (SD) rats. The BBB transport of PBN was investigated in SD rats using internal carotid artery perfusion (ICAP) method at a rate of 4 mι/min for 15 second. We also obtained pharmacokinetic parameters of PBN using single intravenous injection technique. When we estimated BBB permeability of PBN with ICAP method, the brain volume of distribution of PBN was 60.0 $\pm$ 12.0 $\mu\textrm{g}$/ι. The brain uptake of PBN after IV injection at 120 min was 0.15 $\pm$ 0.01%ID/g. The PBN was transported to the brain through the BBB well in rats, because PBN is small molecule (MW 177) and lipid-soluble (log P 1.23) compound.

The Effect of Centrally Active Antihypertensive Agent on Biosynthetic Enzyme Activity of Neurotransmitter in Brain (중추성 항고혈압약이 뇌내 신경전달물질의 생합성 효소에 미치는 영향)

  • 윤재순
    • YAKHAK HOEJI
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    • v.29 no.4
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    • pp.165-175
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    • 1985
  • It has been reported that clonidine is $\alpha_2$-adrenergic agonist, potnet new hypotensive drug in human with low dose. The change in blood pressure is implicated in the concentration, release, uptake and metabalism of catecholamine and activity of catecholamine synthesizing enzyme in specific brain areas. Thus the experiment was set up to investigate the effect on the enzyme activity of clonidine alone and that of clonidine pretreated with imipramine or tranylcypromine by measuring activity of the Dopa-forming enzyme, tyrosine hydroxylase (TH) and epinephrine forming enzyme, phenylethanolamine-N-methyl transferase (PNMT) in brain and adrenal gland. The TH activity in brainstem and substantia nigra is decreased by intraperitoneally administered clonidine 0.1mg/kg twice a day for 5 days, but increased in the rats pretreated with imipramine 10mg/kg intraperitoneally given 26 hrs and 5 hrs before decaptitation. However the TH activity in all regions of brain is increased in rats pretreated with tranylcypromine 10mg/kg intraperitoneally twice a day for 5 days. The effect of clonidine on TH activity is due to inhibition release of norepinephrine by activation of presynaptic $\alpha_2$-adrenoreceptor, axon terminal result in the decrease of TH activity in brain. The increasing of TH activity in brain results in attenuation of the role of clonidine by pretreated with imipramine or tranylcypromine in rats. The activity of PNMT was not significantly affected by clonidine, imipramine and tranylcypromine in adrenal gland.

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