• Animal cells and systems
• /
• v.4 no.1
• /
• pp.63-70
• /
• 2000

The distribution of receptor subtypes for endothelin (ET) in the kidney of the freshwater turtle, Amyda japonica, was examined by quantitative in vitro receptor autoradiography using iodinatd mammalian type ET-1 ($^125$/I-ET-1)as a radiolabeled ligand. Specific $^125$/I-ET-1 bindings were localized to renal tubules, renal arteries and ureter with binding densities of 111.21 $\pm$ 19.14, 182.13$\pm$10.57 and 219.46$\pm$12.83 amol/$mm^2$. respectively. Binding dissociation constants in renal tubules, renal arteries and ureter were 1.05 $\pm$ 0.63, 2.03 $\pm$0.56 and 1.70$\pm$0.47nM, respectively. Receptor subtypes for ET in the kidney were characterized by competition with BQ 123 and BQ 788 as specific antagonists for ET receptors, type A (ET$_A$ ), and type B (ET$_B$) subtypes, respectively. Specific $^125$/I-ET-1 bindings in renal arteries and ureter were potently inhibited by BQ 123 in a dose-dependent manner, whereas BQ 788 was not in competing for specific $^125$/I-ET-1 bindings in this structure. However, specific $^125$/I-ET-1 bindings in renal tubules were inhibited more potently by BQ 788. Therefore, these results indicate that specific ET receptors are localized in renal tubules, renal arteries and the ureter of the freshwater turtle. Results also suggest that the predominant ET receptor subtypes are like the ETA receptor in renal arteries and ureter, and like the ET/$_A$ receptor in the renal tubule.

• The Korean Journal of Physiology and Pharmacology
• /
• v.4 no.4
• /
• pp.275-281
• /
• 2000

Cholecystokinin (CCK) is a gastrointestinal hormone which plays an important role in satiety and gastric motility. It is also widely distributed throughout the central nervous system, where it appears to be involved in the central control of anxiety, feeding behavior and nociception. Two distinct CCK receptor types, $CCK_A$ and $CCK_B,$ have been found in the brain. Both CCK receptors coexist in the rat nucleus tractus solitarius (NTS), which is the primary center for the coordination of peripheral and central activities related to gastrointestinal, cardiovascular and respiratory functions. In order to study ionic actions of CCK on each type of receptor, we investigated the effects of CCK-8S on neurons located in the NTS of the rat using whole-cell patch-clamp recordings in brainstem slices. Application of CCK-8S, under current clamp, produced a membrane depolarization accompanied by action potential firing. This CCK-evoked excitation was dose-dependent $(10\;nM{\sim}10\;{\mu}M)$ and observed in more than 60% of NTS neurons. Under voltage clamp conditions, CCK-8S induced an inward current with a notably increased spontaneous excitatory synaptic activity. However, CCK-8S did not significantly change the amplitude of pharmacologically isolated and evoked EPSP(C)s. Using selective $CCK_A$ and $CCK_B$ receptor antagonists, we observed two different effects of CCK-8S, which suggest $CCK_A$ receptor-mediated inhibitory and $CCK_B$ receptor-mediated excitatory effects in the NTS. These results may help to explain the ability of CCK to modulate gastrointestinal and other reflex systems in the NTS.

• Biomolecules & Therapeutics
• /
• v.8 no.4
• /
• pp.285-292
• /
• 2000

The effects of the members of the same nuclear receptor superfamily (all-trans retinoic acid (RA), thyroid hormone(T3) or hydrocortisone) on proliferation and differentiation in the SK-N-SH neuroblastoma (NB) cell lines were studied. NB cells were treated with RA, T3, or hydrocortisone at concentration of 10$^{-6}$ M or 10$^{-8}$ M for 3 days or 7 days. RA induced concentration- and time-dependent morphologic differentiation(neurite outgrowth and microtubule-associated protein expression) and growth inhibition in NB cells. Treatment of 10$^{-7}$ M T3 for 7 days increased viability and differentiation of NB cells. Treatment of 10$^{-6}$ M hydrocortisone for 7 days increased viability of NB cells. Although these three effectors are members of the same receptor superfamily, the regulation of brain development may be carried out in a different manner.

• Natural Product Sciences
• /
• v.22 no.4
• /
• pp.246-251
• /
• 2016

This study investigated the effects of (-)-sesamin on memory deficits in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned mouse model of Parkinson's disease (PD). MPTP lesion (30 mg/kg/day, 5 days) in mice showed memory deficits including habit learning memory and spatial memory. However, treatment with (-)-sesamin (25 and 50 mg/kg) for 21 days ameliorated memory deficits in MPTP-lesioned mouse model of PD: (-)-sesamin at both doses improved decreases in the retention latency time of the passive avoidance test and the levels of dopamine, norepinephrine, 3,4-dihydroxyphenylacetic acid, and homovanillic acid, improved the decreased transfer latency time of the elevated plus-maze test, reduced the increased expression of N-methyl-D-aspartate (NMDA) receptor, and increased the reduced phosphorylation of extracellular signal-regulated kinase (ERK1/2) and cyclic AMP-response element binding protein (CREB). These results suggest that (-)-sesamin has protective effects on both habit learning memory and spatial memory deficits via the dopaminergic neurons and NMDA receptor-ERK1/2-CREB system in MPTP-lesioned mouse model of PD, respectively. Therefore, (-)-sesamin may serve as an adjuvant phytonutrient for memory deficits in PD patients.

• Animal Bioscience
• /
• v.35 no.3
• /
• pp.367-376
• /
• 2022

Objective: The highly pathogenic avian influenza virus (HPAIV) is a threat to the poultry industry as well as the economy and remains a potential source of pandemic infection in humans. Antiviral genes are considered a potential factor for HPAIV resistance. Therefore, in this study, we investigated gene expression related to cytokine-cytokine receptor interactions by comparing resistant and susceptible Ri chicken lines for avian influenza virus infection. Methods: Ri chickens of resistant (Mx/A; BF2/B21) and susceptible (Mx/G; BF2/B13) lines were selected by genotyping the Mx dynamin like GTPase (Mx) and major histocompatibility complex class I antigen BF2 genes. These chickens were then infected with influenza A virus subtype H5N1, and their lung tissues were collected for RNA sequencing. Results: In total, 972 differentially expressed genes (DEGs) were observed between resistant and susceptible Ri chickens, according to the gene ontology and Kyoto encyclopedia of genes and genomes pathways. In particular, DEGs associated with cytokine-cytokine receptor interactions were most abundant. The expression levels of cytokines (interleukin-1β [IL-1β], IL-6, IL-8, and IL-18), chemokines (C-C Motif chemokine ligand 4 [CCL4] and CCL17), interferons (IFN-γ), and IFN-stimulated genes (Mx1, CCL19, 2'-5'-oligoadenylate synthase-like, and protein kinase R) were higher in H5N1-resistant chickens than in H5N1-susceptible chickens. Conclusion: Resistant chickens show stronger immune responses and antiviral activity (cytokines, chemokines, and IFN-stimulated genes) than those of susceptible chickens against HPAIV infection.

• Journal of Life Science
• /
• v.19 no.4
• /
• pp.532-537
• /
• 2009

Previous studies reported that the N-methyl-D-aspartate (NMDA) receptor is related to alcohol dependence in terms of developing withdrawal or tolerance, however, it is controversial whether NMDA receptor antagonists are effective in preventing relapse in alcohol-dependent patients or not. The purpose of this study was to investigate the effect of memantine, an NMDA receptor antagonist, on alcohol intake in C57BL/6 mice, which prefer drinking hereditarily. Using limited access procedures in C57BL/6 mice in the state of alcohol dependence, vehicle, naltrexone 1.0 mg/kg or, memantine 5, 25, or 50 mg/kg i.p. was administered respectively for twelve days. Medication effects on 2-hours alcohol, 22-hour water, and 24-hour food intake and body weight were studied. Using repeated measure ANOVA, the naltrexone 1 mg/kg, memantine 5, 25, or 50 mg/kg, and vehicle groups showed significant medication by day interaction (naltrexone, df=4, F=11.827, p<0.01, memantine 5 mg/kg, df=4, F=7.999, p<0.01; memantine 25 mg/kg, df=4, F=6.199, p<0.05; memantine 50 mg/kg, df=4, F=10.522, p<0.01) in 2-hour alcohol intake. In 3 memantine groups, there was no significant medication by day interaction with the vehicle group in 22-hour water intake, 24-hour food intake, or body weight. The naltrexone and vehicle groups showed significant medication by day interaction in body weight, but not in 22-hour water or 24-hour food intake. From these results, it is suggested that memantine treatment can affect alcohol intake in mice. Therefore, it is possible that a pure NMDA receptor antagonist is effective in preventing relapse in alcohol-dependent patients.

• IMMUNE NETWORK
• /
• v.7 no.4
• /
• pp.179-185
• /
• 2007

Background: Adenovirus (Ad) vectors have been widely used for many gene therapy applications because of their high transduction ability and broad tropism. However, their utility for cancer gene therapy is limited by their poor transduction into cancer cells lacking the primary receptor, coxsackievirus and adenovirus receptor (CAR). Methods: To achieve CAR-independent gene transfer via Ad, we pretreated Ad with 1,2-dioleoyl-3-trimethylammonium propane (DOTAP) and analyzed their transduction efficiency into cancer cells in vitro and in vivo comparing with the virus alone. Results: Treatment of DOTAP significantly increased adenoviral gene transfer in tumor cells in vitro. Moreover, DOTAP at an optimum dose $(10{\mu}g/ml)$ enhanced IL-12 transgene expression by fivefold in tumor, and twofold in serum after intratumoral injection of adenovirus expressing IL-12N220L (Ad/IL-12N220L). In addition, cotreatment of DOTAP decreased tumor growth rate in the Ad/IL-12N220L-transduced tumor model, finally leading to enhanced survival rate. Conclusion: Our results strongly suggest that DOTAP could be of great utility for improving adenovirus-mediated cancer gene therapy.

• Clinical and Experimental Reproductive Medicine
• /
• v.13 no.2
• /
• pp.187-193
• /
• 1986

The purpose of this study was to establish optimal conditions for progesterone receptor assay using rat uterus, therby applying this system to understand action mechanism of progesterone in female reproductive organ and to evaluate physiological and pathological conditions in female reproduction. The results obtained were as follows 1. $^3H-R5020$ seemed to be more stable than 3H-progesterone as a ligand. 2. Optimal incubation time for ligand and receptor binding was 4-5 hrs at $4^{\circ}C$. 3. For the separation of bond and free ligand, optimal charcoal incubation time was 20 mins. 4. 2-3 mg cytosolic protein/ml was optimal for the binding of ligand. 5. Endogenous progesterone did not influence binding of ligand and receptor unless endogenous progesterone levels were extremely high as in case of pregnancy. 6. Dissociation rate for progesterone receptor was 1.22 nM. 7. $^3H-R5020$ did not bind to corticoid binding globulin (CBG), suggesting that addition of cortisol is saturate CBG was, not necessary as far as $^3H-R5020$ was used as a radioligand. It is, therefore, considered that this assay system established with these conditions might be used for the research as well as clinical routine purposes.

• The Korean Journal of Pharmacology
• /
• v.32 no.1
• /
• pp.1-11
• /
• 1996

Since it has been reported that the depolarization-induced norepinephrine (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 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. The adenosine effects were significantly inhibited by 8-cyclopentyl-1,3-dipropylxanthine (DPCPX, $2{\mu}M$), a selective $A_1-receptor$ antagonist. The responses to N-ethylmaleimide (NEM, 10 & $30{\mu}M$), a SH-alkylating agent of G-protein, were characterized by increments of the evoked NE-release and the basal release, and the adenosine effects were completely abolished by NEM pretreatment. $4{\beta}-Phorbol$ 12,13-dibutyrate (PDB, $1{\mu}M$), a specific protein kinase C (PKC) activator, increased the evoked NE release, whereas polymyxin B sulfate (PMB,0.1 mg), a PKC inhibitor, decreased the release, and the adenosine effects were inhibited by these agents. Nifedipine $(1{\mu}M)$, a $Ca^{2+}-channel$ blocker of dihydropyridine analogue, did not affect the adenosine effect. Tetraethylammonium (TEA, 3 mM) increased the evoked NE release, and inhibited the adenosine effects, but glibenclamide, a ATP dependent $K^+-channel$ blocker, did not. Finally, 8-bromo cyclic AMP (100 & $300{\mu}M$), a membrane-permeable analogue of cAMP, did not alter the NE release, but adenosine effects were inhibited by pretreatment with 8br-cAMP. These results suggest that the decrement of the evoked NE-release by $A_1-adenosine$ receptor is mediated by the C-protein, which is coupled to protein kinase C, adenylate cyclase system and TEA sensitive $K^+-channel$, and that nifedipine-sensitive $Ca^{2+}-channel$ and glibenclamide-sensitive $K^+-channel$ are not involved in this process.

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