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Cladophora glomerata Kützing extract exhibits antioxidant, anti-inflammation, and anti-nitrosative stress against impairment of renal organic anion transport in an in vivo study

  • Atcharaporn Ontawong;Chaliya J. Aida;Pornpun Vivithanaporn;Doungporn Amornlerdpiso;Chutima S. Vaddhanaphuti
    • Nutrition Research and Practice
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    • v.18 no.5
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    • pp.633-646
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    • 2024
  • BACKGROUND/OBJECTIVES: Cladophora glomerata extract (CGE), rich in polyphenols, was reported to exhibit antidiabetic and renoprotective effects by modulating the functions of protein kinases-mediated organic anion transporter 1 (Oat1) and 3 (Oat3) in rats with type 2 diabetes mellitus (T2DM). Nevertheless, the antioxidant effects of CGE on such renoprotection have not been investigated. This study examined the mechanisms involved in the antioxidant effects of CGE on renal organic anion transport function in an in vivo study. MATERIALS/METHODS: Diabetes was induced in the rats through a high-fat diet combined with a single dose of 40 mg/kg body weight (BW) streptozotocin. Subsequently, normal-diet rats were supplemented with a vehicle or 1,000 mg/kg BW of CGE, while T2DM rats were supplemented with a vehicle, CGE, or 200 mg/kg BW of vitamin C for 12 weeks. The study evaluated the general characteristics of T2DM and renal oxidative stress markers. The renal organic transport function was assessed by measuring the para-aminohippurate (PAH) uptake using renal cortical slices and renal inflammatory cytokine expression in the normal diet (ND) and ND + CGE treated groups. RESULTS: CGE supplementation significantly reduced hyperglycemia, hypertriglyceridemia, insulin resistance, and renal lipid peroxidation in T2DM rats. This was accompanied by the normalization of high expressions of renal glutathione peroxidase and nuclear factor kappa B by CGE and vitamin C. The renal anti-inflammation of CGE was evidenced by the reduction of tumor necrosis factor-1α and interleukin-1β. CGE directly blunted sodium nitroprusside-induced renal oxidative/nitrosative stresses and mediated the PAH uptake in the normally treated CGE in rats was particularly noteworthy. These data also correlated with reduced nitric oxide production, highlighting the potential of CGE as a therapeutic agent for managing T2DM-related renal complications. CONCLUSION: These findings suggest that CGE has antidiabetic effects and directly prevents diabetic nephropathy through oxidative/nitrosative stress pathways.

Time Course Change of Phagocytes and Proinflammatory Activities in BALF in Endotoxin-induced Acute Lung Injury (시간별 내독소 정맥주입으로 유발된 급성폐손상의 변화양상에 대한 고찰)

  • Moon, Seung-Hyug;Oh, Je-Ho;Park, Sung-Woo;NamGung, Eun-Kyung;Ki, Shin-Young;Im, Gun-Il;Jung, Sung-Whan;Kim, Hyeon-Tae;Uh, Soo-Tack;Kim, Yong-Hoon;Park, Choon-Sik;Jin, Byeng-Weon
    • Tuberculosis and Respiratory Diseases
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    • v.44 no.2
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    • pp.360-378
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    • 1997
  • Background : Severe acute lung injury(ALI), also known as the adult respiratory distress syndrome(ARDS), is a heterogenous nature of dynamic and explosive clinical synrome that exacts a mortality of approximately 50%. Endotoxin(ETX) is an abundant component of the outer membrane of gram-negative bacteria capable of inducing severe lung injury in gram-negative sepsis and gram-negative bacterial pneumonia, which are among the most common predisposing causes of ARDS. The influx of PMNs into airway tissue is a pathological hallmark of LPS-induced lung injury. And there is a substantial evidence suggesting that cytokines are important mediators of lung injury in gram-negative sepsis. However, the kinetics of phagocytes and cytokines by an exact time sequence and their respective pathogenic importance remain to be elucidated. This study was performed to investigate the role of phagocytes and proinflammatory cytokines in ETX-induced ALI through a time course of changes in the concentration of protein, $TNF{\alpha}$ and IL-6, and counts of total and its differential cells in BALF. The consecutive histologic findings were also evaluated. Method : The experimental animals, healthy male Sprague-Dawley, weighted $200{\pm}50g$, were divided into control- and ALI- group. ALI was induced by an intravenous administration of ETX, 5mg/kg. Above mentioned all parameters were examined at 0(control), 3, 6, 24, 72 h after administration of ETX. $TNF{\alpha}$ and IL-6 cone. in BALF were measured by a bioassay. Results : The protein concentration and total leukocyte count(TC) in BALF was significantly increased at 3h compared to controls(p < 0.05). The protein conc. was significantly elavated during observation period, but TC was significantly decreased at 72h(p < 0.05 vs. 24h). There was a close relationship between TC and protein cone. in BALF(r = 0.65, p < 0.001). The PMN and monocyte count was well correlated with TC in BALF, and the correlation of PMN(r = 0.97, p < 0.001) appeared to be more meaningful than that of monocyte(r = 0.61, p < 0.001). There was also a significant correlation between protein cone. and PMN or monocyte count in BALF(PMN vs. monocyte : r = 0.55, p < 0.005 vs. r = 0.64, p < 0.001). The count of monocyte was significantly elavated during observation period though a meaningful reduction of PMN count in BALF at 72h, this observation suggested that monocyte may, at least, partipate in the process of lung injury steadly. In this study, there was no relationship between IL-6 and $TNF{\alpha}$ cone., and $TNF{\alpha}$ but not IL-6 was correlated with TC(r = 0.61, p < 0.05) and monocyte(r = 0.67, p < 0.05) in BALF only at 3, 6h after ETX introduced. In particular, the IL-6 cone. increased earlier and rapidly peaked than $TNF{\alpha}$ cone. in BALF. In histologic findings, the cell counts of lung slices were increased from 3 to 72h(p < 0.001 vs. NC). Alveolar wall-thickness was increased from 6 to 24h(p < 0.001 vs. NC). There was a significant correlation between the cell counts of lung slices and alveolar wall-thickness(r= 0.61, p < 0.001). This result suggested that the cellular infiltrations might be followed by the alterations of interstitium, and the edematous change of alveolar wall might be most rapidly recovered to its normal condition in the process of repair. Conclusion : We concluded that although the role of PMN is partly certain in ETX-induced ALI, it is somewhat inadequate to its known major impact on ALL Alveolar macrophage and/or non-immune cells such as pulmonary endothelial or epithelial cells, may be more importantly contributed to the initiation and perpetual progression of ETX-induced ALI. The IL-6 in ETX-induced ALI was independent to $TNF{\alpha}$, measured by a bioassay in BALF. The early rise in IL-6 in BALF implies multiple origins of the IL-6.

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A STUDY OF THE NORMAL & ABNORMAL OCCULSAL PATERNS IN ADULTS USING THE SUPERIMPOSED RUBBER PATTERN METHOD (Superimposed Rubber Pattern법에 의한 성인 정상 및 비정상 교합자의 교합 양상에 관한 연구)

  • Choi, Dae-Gyun;Lee, Sung-Bok;Kwon, Young-Hyuk;Choi, Boo-Byung
    • The Journal of Korean Academy of Prosthodontics
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    • v.33 no.3
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    • pp.467-491
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    • 1995
  • In order to analyze the occlusin of intercuspation with maximun bite force, fifteen healthy adult subjects with the ages 23 to 27 were studied(Group1 ; 5-normal occlusion with Angle's Class1, Group2 ; 5-Angle's Class2 malocclusion, Group3 ; 5-Angle’s Class3 malocclusion). Head Position was fixed with occlusal plane paralleling to horizontal line and occlusal registration r cord was made with polyether rubber impression material(Ramitec, ESPECo. West Germany). After all subject were trained for maximum intercuspation at least 5 times, occlusal registration procedure was repeated for this study. Lower posterior rubber occlusal registration records were sliced with 1mm thickness using precision metal sliding channel(Hitachi Ind. Co., Japan). Gross sectional drawings were traced from occluding view of upper and lower posterior teeth on the rubber slices using digitizer, and superimposed for the determination of each drawing distance(Superimposed Rubber Pattern Method). Based on superimposed rubber pattern drawings, total area of occlusal view, sum of each area of the 5 divided occlusal contact provinces and its ratio, total area and number of occlusal contact area were determined to elucidate occlusal stability in the normal and abnormal occlusion groups. The data were analysed by t-test(p=0.05) to determine statistical significance. The obtained results were as follows : 1. Group1 showed the largest standard area with occlusal view of the lower posterior teeth and Group3 showed the smallest area. There was a significant difference between Group2 and Group3(p=0.025), and Gropu1 was not statistically different for both Group2 and Group3. 2. Means and ratio of the under 2.0mm area(D) and ratio showed $197.49mm^2$, 59.76% in Group1, $188,69mm^2$, 56.10% in Group2, and $174.23mm^2$, 55.76% in Group3. The results that Group1 has the most area/ratio and Group3 has the least area/ratio can be considered Group1 is the most advantageous for masticatory effective area, and Group3 is the least adnantageous. 3. Means and ratio of the under 1.0mm area(C) were $198.96mm^2$, 42.65% in Group1, 123.06$mm^2$, 46.58% in Group2, and $92.24mm^2$, 29.52% in Group3. These data means that Group1 is the most advantageous in terms of masticatory effective area and Group3 is the least. 4. Means and ratio of the under 0.5mm area(B) were $86.68mm^2$, 26.68% in Group1, $62.98mm^2$, 18.71% in Group2, and $36.44mm^2$, 11.66% in Group3. These can also be considered Group1 is the most advantageous for masticatory effective area and occlusal stability. 5. Means and ratio of the under 0.05mm area(A) were $30.92mm^2$, 9.21% in Group1, $14.31mm^2$, 4.25% in Group2, and $7.59mm^2$, 2.43% in Group3. The area ratio of the each subject group was(4.1) : (1.9) : (1)and the data of the under 0.05mm area has the intimate relationship with inter-group and intra-group data/ratio. 6. First molar showed the most occlusal contact points in all subject group and Group1 showed somewhat uniformly distributed occlusal contact point except first premolar. In Group2, all contact point in posterior teeth showed significantly reduced distribution except first molar. Group3 showed evenly distributed contace points in first and second molars.

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A Study on the Menu Development for the Elderly during Busy Farming Season in Gyeongbuk Andong (경북 안동시 농번기 농촌노인 식단개발 연구)

  • Kim, Hae-Young;Park, Chan-Eun;Lee, Hae-Jin;Park, Young-Hee;Lee, Jin-Young
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.10
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    • pp.1381-1391
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    • 2009
  • Dietary life style of the elderly living in rural areas of Gyeongbuk Andong during the busy farming season was surveyed and a monthly meal plan for the elderly was developed using eco-friendly native crops and considering the characteristics of a busy farming season and their preferences. A week meal plan was selected and applied to those fields. The meal plan was developed for an elder's house in Gyeongbuk Andong during the busy farming season. Especially, to increase the intake of calcium and dietary fiber, bamboo sprouts, pepper leaves, dried slices of whitebait, and fried anchovies were used. Considering the busy farming season, the ginseng chicken soup and the soybean noodle soup were served to provide high quality of protein and to improve health condition. A cold soup of cucumber and brown seaweed was used to supplement liquid, vitamins, and minerals. The results are as follows: the highest score of the preference on a staple was 8.77 for the boiled barley of menu 5; the favorite soup was the ginseng chicken soup (8.73) in menu 4; for side dishes, those in menu 5 were most popular (8.69); the favorite meal was the ginseng chicken soup of menu 4 (8.69). Regarding the amount of leftover foods, the lightest was 30.14 g in Gyeongbuk Andong menu 3 which significantly indicates high preference (p<0.05). The current study was a planned meal service menu using local crops and seasonal foods, which was actually applied to the field resulting in high preference and satisfaction levels.

Changes of c-Fos Immunoreactivity in Midbrain by Deep Pain and Effects of Aspirin (심부통증이 흰쥐 중뇌에 미치는 c-Fos 면역반응성의 변화와 아스피린의 효과)

  • Jung, Jin A;Yoo, Ki Soo;Hwang, Kyu Keun
    • Clinical and Experimental Pediatrics
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    • v.46 no.7
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    • pp.695-701
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    • 2003
  • Purpose : It had been suggested that pain arising from deep somatic body regions influences neural activity within periaqueductal gray(PAG) of midbrain via distinct spinal pathways. Aspirin is one of the popular non-steroidal anti-inflammatory drugs used in the management of pain. Fos expression was used as a marker for neuronal activity throughout central neurons following painful peripheral stimulation. This study was prepared to investigate changes of c-Fos immunoreactivity in midbrain by deep pain and effects of aspirin. Methods : Male Sprague-Dawley rats were injected with 0.1 mL of 5% formalin in the plantar muscle of the right hindpaw. For experimental group II, aspirin was injected intravenously before injection of formalin. An aspirin-untreated group was utilized as group I. Rats were sacrificed at 0.5, 1, 2, 6 and 24 hours after formalin injection. Rat's brains were removed and sliced in rat brain matrix. Brain slices were coronally sectioned at interaural 1.00-1.36 mm. Serial sections were immunohistochemically reacted with polyclonal c-Fos antibody. The numbers of c-Fos protein immunoreactive neurons in ventrolateral periaqueductal gray(VLPAG) and dorsomedial periaqueductal gray(DMPAG) were counted and analyzed statistically with Mann-Whitney U tests. Results : Higher numbers of c-Fos protein immunoreactive neurons were found in VLPAG. In both VLPAG and DMPAG of formalin-treated group, the numbers of c-Fos protein immunoreactive neurons were significantly higher at all time points than the formalin-untreated group, which peaked at two hours. The numbers of c-Fos immunoreactive neuron of the aspirin-treated group were less compared to the aspirin-untreated group at each time point. Conclusion : These results provide some basic knowledge in understanding the mechanism of formalin-induced deep somatic pain and the effects of aspirin.

Quantitative Study of Annular Single-Crystal Brain SPECT (원형단일결정을 이용한 SPECT의 정량화 연구)

  • 김희중;김한명;소수길;봉정균;이종두
    • Progress in Medical Physics
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    • v.9 no.3
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    • pp.163-173
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    • 1998
  • Nuclear medicine emission computed tomography(ECT) can be very useful to diagnose early stage of neuronal diseases and to measure theraputic results objectively, if we can quantitate energy metabolism, blood flow, biochemical processes, or dopamine receptor and transporter using ECT. However, physical factors including attenuation, scatter, partial volume effect, noise, and reconstruction algorithm make it very difficult to quantitate independent of type of SPECT. In this study, we quantitated the effects of attenuation and scatter using brain SPECT and three-dimensional brain phantom with and without applying their correction methods. Dual energy window method was applied for scatter correction. The photopeak energy window and scatter energy window were set to 140ke${\pm}$10% and 119ke${\pm}$6% and 100% of scatter window data were subtracted from the photopeak window prior to reconstruction. The projection data were reconstructed using Butterworth filter with cutoff frequency of 0.95cycles/cm and order of 10. Attenuation correction was done by Chang's method with attenuation coefficients of 0.12/cm and 0.15/cm for the reconstruction data without scatter correction and with scatter correction, respectively. For quantitation, regions of interest (ROIs) were drawn on the three slices selected at the level of the basal ganglia. Without scatter correction, the ratios of ROI average values between basal ganglia and background with attenuation correction and without attenuation correction were 2.2 and 2.1, respectively. However, the ratios between basal ganglia and background were very similar for with and without attenuation correction. With scatter correction, the ratios of ROI average values between basal ganglia and background with attenuation correction and without attenuation correction were 2.69 and 2.64, respectively. These results indicate that the attenuation correction is necessary for the quantitation. When true ratios between basal ganglia and background were 6.58, 4.68, 1.86, the measured ratios with scatter and attenuation correction were 76%, 80%, 82% of their true ratios, respectively. The approximate 20% underestimation could be partially due to the effect of partial volume and reconstruction algorithm which we have not investigated in this study, and partially due to imperfect scatter and attenuation correction methods that we have applied in consideration of clinical applications.

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Perfusion MR Imaging of the Brain Tumor: Preliminary Report (뇌종야의 관류 자기공명영상: 예비보고)

  • 김홍대;장기현;성수옥;한문희;한만청
    • Investigative Magnetic Resonance Imaging
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    • v.1 no.1
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    • pp.119-124
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    • 1997
  • Purpose: To assess the utility of magnetic resonance(MR) cerebral blood volume (CBV) map in the evaluation of brain tumors. Materials and Methods: We performed perfusion MR imaing preoperatively in the consecutive IS patients with intracranial masses(3 meningiomas, 2 glioblastoma multiformes, 3 low grade gliomas, 1 lymphoma, 1 germinoma, 1 neurocytoma, 1 metastasis, 2 abscesses, 1 radionecrosis). The average age of the patients was 42 years (22yr -68yr), composed of 10 males and S females. All MR images were obtained at l.ST imager(Signa, CE Medical Systems, Milwaukee, Wisconsin). The regional CBV map was obtained on the theoretical basis of susceptibility difference induced by first pass circulation of contrast media. (contrast media: IScc of gadopentate dimeglumine, about 2ml/sec by hand, starting at 10 second after first baseline scan). For each patient, a total of 480 images (6 slices, 80 images/slice in 160 sec) were obtained by using gradient echo(CE) single shot echo-planar image(EPI) sequence (TR 2000ms, TE SOms, flip angle $90^{\circ}$, FOV $240{\times}240mm,{\;}matrix{\;}128{\times}128$, slice-thick/gap S/2.S). After data collection, the raw data were transferred to CE workstation and rCBV maps were generated from the numerical integration of ${\Delta}R2^{*} on a voxel by voxel basis, with home made software (${\Delta}R2^{*}=-ln (S/SO)/TE). For easy visual interpretation, relative RCB color coding with reference to the normal white matter was applied and color rCBV maps were obtained. The findings of perfusion MR image were retrospectively correlated with Cd-enhanced images with focus on the degree and extent of perfusion and contrast enhancement. Results: Two cases of glioblastoma multiforme with rim enhancement on Cd-enhanced Tl weighted image showed increased perfusion in the peripheral rim and decreased perfusion in the central necrosis portion. The low grade gliomas appeared as a low perfusion area with poorly defined margin. In 2 cases of brain abscess, the degree of perfusion was similar to that of the normal white matter in the peripheral enhancing rim and was low in the central portion. All meningiomas showed diffuse homogeneous increased perfusion of moderate or high degree. One each of lymphoma and germinoma showed homogenously decreased perfusion with well defined margin. The central neurocytoma showed multifocal increased perfusion areas of moderate or high degree. A few nodules of the multiple metastasis showed increased perfusion of moderate degree. One radionecrosis revealed multiple foci of increased perfusion within the area of decreased perfusion. Conclusion: The rCBV map appears to correlate well with the perfusion state of brain tumor, and may be helpful in discrimination between low grade and high grade gliomas. The further study is needed to clarify the role of perfusion MR image in the evaluation of brain tumor.

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Functional MR Imaging of Cerbral Motor Cortex: Comparison between Conventional Gradient Echo and EPI Techniques (뇌 운동피질의 기능적 영상: 고식적 Gradient Echo기법과 EPI기법간의 비교)

  • 송인찬
    • Investigative Magnetic Resonance Imaging
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    • v.1 no.1
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    • pp.109-113
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    • 1997
  • Purpose: To evaluate the differences of functional imaging patterns between conventional spoiled gradient echo (SPGR) and echo planar imaging (EPI) methods in cerebral motor cortex activation. Materials and Methods: Functional MR imaging of cerebral motor cortex activation was examined on a 1.5T MR unit with SPGR (TRfrE/flip angle=50ms/4Oms/$30^{\circ}$, FOV=300mm, matrix $size=256{\times}256$, slice thickness=5mm) and an interleaved single shot gradient echo EPI (TRfrE/flip angle = 3000ms/40ms/$90^{\circ}$, FOV=300mm, matrix $size=128{\times}128$, slice thickness=5mm) techniques in five male healthy volunteers. A total of 160 images in one slice and 960 images in 6 slices were obtained with SPGR and EPI, respectively. A right finger movement was accomplished with a paradigm of an 8 activation/ 8 rest periods. The cross-correlation was used for a statistical mapping algorithm. We evaluated any differences of the time series and the signal intensity changes between the rest and activation periods obtained with two techniques. Also, the locations and areas of the activation sites were compared between two techniques. Results: The activation sites in the motor cortex were accurately localized with both methods. In the signal intensity changes between the rest and activation periods at the activation regions, no significant differences were found between EPI and SPGR. Signal to noise ratio (SNR) of the time series data was higher in EPI than in SPGR by two folds. Also, larger pixels were distributed over small p-values at the activation sites in EPI. Conclusions: Good quality functional MR imaging of the cerebral motor cortex activation could be obtained with both SPGR and EPI. However, EPI is preferable because it provides more precise information on hemodynamics related to neural activities than SPGR due to high sensitivity.

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Effect of $K^+-channel$ Blockers on the $A_1-adenosine$ Receptor-Coupled Regulation of Electrically-Evoked Norepinephrine Release in the Rat Hippocampus (흰쥐 해마에서 Norepinephrine 유리를 조절하는 $A_1-adenosine$ 수용체의 역할에 미치는 $K^+$ 통로 차단제의 영향)

  • Choi, Bong-Kyu;Kim, Sang-Hoon
    • The Korean Journal of Pharmacology
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    • v.32 no.3
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    • pp.301-309
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    • 1996
  • Since it has been reported that the depolarization-induced NE release is inhibited by activation of presynaptic $A_1-adenosine$ heteroreceptor in hippocampus, a large body of experimental data on the post-receptor mechanism of this process has been accumulated. But, the post-receptor mechanism of presynaptic $A_1-adenosine$ receptor on the NE release has not been clearly elucidated yet. Therefore, it was attempted to clarify the participation of $K^+-channel$ in the post-receptor mechanisms of the $A_1-adenosine$ receptor-mediated control of NE release in this study. Slices from rat hippocampus were equilibrated with $^3H-norepinephrine$ and the release of the labelled products was evoked by electrical stimulation (3 Hz, 5 $VCm^{-1}$, 2 ms, rectangular pulses), and the influence of various agents on the evoked tritium-outflow was investigated. Adenosine, in concentrations ranging from $1{\sim}30\;{\mu}M$, decreased the NE release in a dose-dependent manner, without affecting the basal rate of release. 4AP $(1{\sim}30{\mu}M)$, a specific A-type $K^+-channel$ blocker, increased the evoked NE release in a dose-related fashion, and the basal rate of release is increased by 10 and $30{\mu}M$. TEA $(1{\sim}10{\mu}\;M)$, a nonspecific $K^+-channel$ blocker, increased the evoked NE release in a dose-dependent manner without affecting basal release. The adenosine effects were significantly inhibites by 3 ${\mu}M$ 4AP and 10 mM TEA treatment. 4AP $(30{\mu}M)-$ and TEA (10 mM)-induced increments of evoked NE release were completely abolished in $Ca^{++} free, but these were recoverd in low $Ca^{++} medium. And the effects of $K^+-channel$ blockers in low $Ca^{++} medium were inhibites and abolishes by $Mg^{++} (4 mM) adding and TTX $(0.3{\mu}M)$ adding medium, respectively. These results suggest that the decrement of the evoked NE-release by $A_1-adenosine$ receptor is mediated by 4AP and TEA sensitive $K^+-channel$.

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The Role of Adenosine Receptors on Acetylcholine Release in the Rat Striatum

  • Kim, Do-Kyung;Kim, Hyeon-A;Choi, Bong-Kyu
    • The Korean Journal of Physiology and Pharmacology
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    • v.1 no.1
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    • pp.1-12
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    • 1997
  • As it has been reported that the depolarization induced acetylcholine (ACh) release is modulated by activation of presynaptic $A_1$ adenosine heteroreceptor and various evidence suggest that indicate the $A_2$ adenosine receptor is present in the striatum, this study was undertaken to delineate the role of adenosine receptors on the striatal ACh release. Slices from the rat striatum 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, $5\;Vcm^{-1}$, 2 min), was measured, and the influence of various agents on the evoked tritium outflow was investigated. And also, quantitative receptor autoradiography and drug-receptor binding assay were performed in order to confirm the presence and characteristics of $A_1$ and $A_2$ adenosine receptors in the rat striatum. Adenosine $(10{sim}100\;{mu}M)$ and $N^6$-cyclopentyladenosine (CPA, $1{sim}100\;{mu}M)$ decreased the $[^3H]$ACh release in a dose-dependent manner without changing the basal rate of release in the rat striatum. The reducing effects of ACh release by adenosine and CPA were abolished by 8-cyclopentyl-1,3-dipropy-Ixanthine (DPCPX, 2 ${mu}M$), a selective $A_1$, adenosine receptor antagonist, treatment. The effect of adenosine was potentiated markedly by 3,7-dimethyl-1-propargylxanthine (DMPX, 10 ${mu}M$), a specific $A_2$ adenosine receptor antagonist. 2-P-(2-carboxyethyl)phenethylamimo-5'-N- ethylcarboxamidoadenosine hydrochloride (CGS-21680C), in concentrations ranging from 0.01 to 10 ${mu}M$, a recently introduced potent $A_2$ adenosine receptor agonist, increased the $[^3H]$ACh release in a dose related fashion without changing the basal rate of release. These effects were completely abolished by DMPX $(10\;{mu}M)$. In autoradiograrhy experiments, $[^3H]$2-chloro-$N^6$-cyclopentyladenosine ($[^3H]$ CCPA) bindings were highly localized in the hippocampus and the cerebral cortex. Additionally, lower levels of binding were found in the striatum. However, $[^3H]$CGS-21680C bindings were highly localized in the striatal region with the greatest density of binding found in the caudate nucleus and putamen. Lower levels of binding were also found in the nucleus accumbens and olfactory tubercle. In drug-receptor binding assay, binding of $[^3H]$ CCPA to $A_1$ adenosine receptors of rat striatal membranes was inhibited by CPA ($K_i$ = 1.6 nM) and N-ethylcarboxamidoadenosine (NECA, $K_i$ = 12.9 nM), but not by CGS-21680C ($K_i$ = 2609.2 nM) and DMPX ($K_i$ = 19,386 nM). In contrast, $[^3H]$CGS-21680C binding to $A_2$ denosine receptors was inhibited by CGS-21680C ($K_i$ = 47.6 nM) and NECA ($K_i$ = 44.9 nM), but not by CPA ($K_i$ = 2099.2 nM) and DPCPX ($K_i$ = 19,207 nM). The results presented here suggest that both types of $A_1$ and $A_2$ adenosine heteroreceptors exist and play an important role in ACh release in the rat striatal cholinergic neurons.

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