• Proceedings of the Korean Society of Life Science Conference
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• 2007.10a
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• pp.85.1-85.1
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• 2007

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• Proceedings of the Korean Biophysical Society Conference
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• 1997.07a
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• pp.32-32
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• 1997

The regulatory role of A$\sub$2A/ adenosine receptors in P$_2$ purinoceptor-mediated calcium signaling was investigated in rat pheochromocytoma (PC12) cells. When PC12 cells were treated with 2-p-(2-carboxyethyl)phenethylamino-5'-N-ethylcarboxamidoadenosine (CGS21680), a specific agonist of the A$\sub$2A/ adenosine receptor, extracellular ATP-evoked [(CA$\^$2+/)]$\sub$i/ rise was inhibited by 20%.(omitted)

• The Korean Journal of Physiology and Pharmacology
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• v.15 no.6
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• pp.339-344
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• 2011

Ulmus davidiana var. japonica Rehder (Urticales: Ulmaceae) (UD) is a tree widespread in northeast Asia. It is traditionally used for anticancer and anti-inflammatory therapy. The present study investigated the effect of an ethanol extract of UD on vascular tension and its underlying mechanism in rats. The dried root bark of UD was ground and extracted with 80% ethanol. The prepared UD extract was used in further analysis. The effect of UD on the cell viability, vasoreactivity and hemodynamics were investigated using propidium iodide staining in cultured cells, isometric tension recording and blood pressure analysis, respectively. Low dose of UD ($10{\sim}100{\mu}g/ml)$ did not affect endothelial cell viability, but high dose of UD reduced cell viability. UD induced vasorelaxation in the range of $0.1{\sim}10{\mu}g/ml$ with an $ED_{50}$ value of $2{\mu}g/ml$. UD-induced vasorelaxation was completely abolished by removal of the endothelium or by pre-treatment with L-NAME, an inhibitor of nitric oxide synthase. UD inhibited calcium influx induced by phenylephrine and high $K^+$ and also completely abolished the effect of L-NAME. Intravenous injection of UD extracts (10~100 mg/kg) decreased arterial and ventricular pressure in a dose-dependent manner. Moreover, UD extracts reduced the ventricular contractility (+dP/dt) in anesthetized rats. However, UD-induced hypotensive actions were minimized in L-NAME-treated rats. Taken together, out results showed that UD induced vasorelaxation and has antihypertensive properties, which may be due the activation of nitric oxide synthase in endothelium.

• Biomolecules & Therapeutics
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• v.18 no.2
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• pp.152-158
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• 2010

Melanin concentrating hormone is a neuropeptide highly expressed in the brain that regulates several physiological functions mediated by receptors in the G-protein coupled receptor family, especially plays an important role in the complex regulation of energy balance and body weight mediated by the melanin concentrating hormone receptor subtype 1 (MCH1). Compelling pharmacological evidence implicating MCH1 signaling in the regulation of food intake and energy expenditure has generated a great deal of interest by pharmaceutical companies as MCH1 antagonists may have potential therapeutic benefit in the treatment of obesity and metabolic syndrome. Although fluorescence-based calcium mobilization assay platform has been one of the most widely accepted tools for receptor research and drug discovery, fluorescence interference and shallow assay window limit their application in high throughput screening and have led to a growing interest in alternative, luminescence-based technologies. Herein, a luminescence-based functional assay system for the MCH1 receptor was developed and validated with the mitochondrial targeted aequorin. Aequorin based functional assay system for MCH1 presented excellent Z' factor (0.8983) and high signal-to-noise ratio (141.9). The nonpeptide MCH1 receptor antagonist, SNAP 7941 and GSK 803430, exhibited $IC_{50}$ values of 0.62 ${\pm}$ 0.11 and 12.29 ${\pm}$ 2.31 nM with excellent correlation coefficient. These results suggest that the aequorin based assay system for MCH1 is a strong alternative to the traditional GPCR related tools such as radioligand binding experiments and fluorescence functional determinations for the compound screening and receptor research.

• International Journal of Oral Biology
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• v.40 no.4
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• pp.211-216
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• 2015

Nitric Oxide (NO) is an important signaling molecule in the nociceptive process. Our previous study suggested that high concentrations of sodium nitroprusside (SNP), a NO donor, induce a membrane hyperpolarization and outward current through large conductances calcium-activated potassium ($BK_{ca}$) channels in substantia gelatinosa (SG) neurons. In this study, patch clamp recording in spinal slices was used to investigate the sources of $Ca^{2+}$ that induces $Ca^{2+}$-activated potassium currents. Application of SNP induced a membrane hyperpolarization, which was significantly inhibited by hemoglobin and 2-(4-carboxyphenyl) -4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide potassium salt (c-PTIO), NO scavengers. SNP-induced hyperpolarization was decreased in the presence of charybdotoxin, a selective $BK_{Ca}$ channel blocker. In addition, SNP-induced response was significantly blocked by pretreatment of thapsigargin which can remove $Ca^{2+}$ in endoplasmic reticulum, and decreased by pretreatment of dentrolene, a ryanodine receptors (RyR) blocker. These data suggested that NO induces a membrane hyperpolarization through $BK_{ca}$ channels, which are activated by intracellular $Ca^{2+}$ increase via activation of RyR of $Ca^{2+}$ stores.

• BMB Reports
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• v.46 no.12
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• pp.600-605
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• 2013

Interplay between calcium ions ($Ca^{2+}$) and reactive oxygen species (ROS) delicately controls diverse pathophysiological functions of vascular smooth muscle cells (VSMCs). However, details of the $Ca^{2+}$ and ROS signaling network have been hindered by the absence of a method for dual measurement of $Ca^{2+}$ and ROS. Here, a real-time monitoring system for $Ca^{2+}$ and ROS was established using a genetically encoded hydrogen peroxide indicator, HyPer, and a ratiometric $Ca^{2+}$ indicator, fura-2. For the simultaneous detection of fura-2 and HyPer signals, 540 nm emission filter and 500 nm~ dichroic beamsplitter were combined with conventional exciters. The wide excitation spectrum of HyPer resulted in marginal cross-contamination with fura-2 signal. However, physiological $Ca^{2+}$ transient and hydrogen peroxide were practically measurable in HyPer-expressing, fura-2-loaded VSMCs. Indeed, distinct $Ca^{2+}$ and ROS signals could be successfully detected in serotonin-stimulated VSMCs. The system established in this study is applicable to studies of crosstalk between $Ca^{2+}$ and ROS.

• Journal of Integrative Natural Science
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• v.17 no.1
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• pp.31-41
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• 2024

Calcium ions play an important role in development and intracellular signaling. Dictyostelium discoideum has 14 genes encoding calcium -binding proteins (CBPs), but the function of most CBPs during development has not yet been studied. In this study, we investigated the specific functions of CBP7, one of 14 CBPs, in development using RNA interference cell lines of CBP7, cell lines overexpressing CBP7, cell lines with point mutations in the EF-hand domain, and cell lines expressing fragment proteins. was intended to reveal. CBP7 consists of 169 amino acids and contains 4EF-hand domains. The CBP7-overexpressing cells showed complete loss of developmental process. These cells remained in the single-cell growth stage under development -inducing conditions, while wild-type cells formed aggregations within 6-8h of development and eventually formed fruiting bodies. The experiments using point-mutated CBP7 protein showed that all EF-hand domains of CBP7 were important for CBP7 to function during developmental process. These results suggest that CBP7 plays an important role in developmental processes across all EF-hand domains.

• Proceedings of the Korean Biophysical Society Conference
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• 1996.07a
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• pp.8-8
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• 1996

The regulatory role of A$\_$2A/ adenosine receptors on the P purinoceptor-mediated calcium signaling was investigated in rat pheochromocytoma (PC 12) cells. When PC 12 cells were treated with 2-p-(2-carboxyethyl) phenethylamino- 5' - N -ethylcarboxamido-adenosine (CGS21680), a specific agonist of the A$\_$2A/ adenosine receptor, extracellular ATP-evoked [Ca$\^$2+/]$\_$I/ rise was inhibited by -20%. (omitted)

• Proceedings of the Korean Biophysical Society Conference
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• 1999.06a
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• pp.67-67
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• 1999

The effect of chlorpromazine on the store-operated Ca$\^$2＋/ entry subsequently activated via the phospholipase C signaling pathway was investigated in PC12 cells. Chlorpromazine caused a rapid decline of the bradykinin-induced Ca$\^$2＋/ increase to basal level without attenuating the peak level.(omitted)

• The Korean Journal of Pain
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• v.33 no.2
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• pp.131-137
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• 2020

Background: Among various diseases that accompany pain, complex regional pain syndrome (CRPS) is one of the most frustrating for patients and physicians. Recently, many studies have shown functional and anatomical abnormalities in the brains of patients with CRPS. The calcium-related signaling pathway is important in various physiologic processes via calmodulin (CaM) and calcium-calmodulin kinase 2 (CaMK2). To investigate the cerebral mechanism of CRPS, we measured changes in CaM and CaMK2 expression in the cerebrum in CRPS animal models. Methods: The chronic post-ischemia pain model was employed for CRPS model generation. After generation of the animal models, the animals were categorized into three groups based on changes in the withdrawal threshold for the affected limb: CRPS-positive (P), CRPS-negative (N), and control (C) groups. Western blot analysis was performed to measure CaM and CaMK2 expression in the rat cerebrum. Results: Animals with a decreased withdrawal threshold (group P) showed a significant increment in cerebral CaM and CaMK2 expression (P = 0.013 and P = 0.021, respectively). However, groups N and C showed no difference in CaM and CaMK2 expression. Conclusions: The calcium-mediated cerebral process occurs after peripheral injury in CRPS, and there can be a relationship between the cerebrum and the pathogenesis of CRPS.