• International Journal of Oral Biology
• /
• v.31 no.4
• /
• pp.127-133
• /
• 2006

[ $H_2O_2$ ], a member of reactive oxygen species (ROS), is known to be involved in the mediation of physiological functions in a variety of cell types. However, little has been known about the physiological role of $H_2O_2$ in exocrine cells. Therefore, in the present study, the effect of $H_2O_2$ on cholecystokinin (CCK)-evoked $Ca^{2+}$ mobilization and amylase release was investigated in rat pancreatic acinar cells. Stimulation of the acinar cells with sulfated octapeptide form of CCK (CCK-8S) induced biphasic increase in amylase release. Addition of $30\;{\mu}M\;H_2O_2$ enhanced amylase release caused by 10 pM CCK-8S, but inhibited the amylase release induced by CCK-8S at concentrations higher than 100 pM. An ROS scavenger, $10\;{\mu}M$ Mn(III)tetrakis(4-benzoic acid)porphyrin chloride, increased amylase release caused by CCK-8S at concentrations higher than 100 pM, although lower concentrations of CCK-8S-induced amylase release was not affected. To examine whether the effect of $H_2O_2$ on CCK-8S-induced amylase release was exerted via modulation of intracellular $Ca^{2+}$ signaling, we measured the changes in intracellular $Ca^{2+}$ concentration $([Ca^{2+}]_i)$ in fura-2 loaded acinar cells. Although $30\;{\mu}M\;H_2O_2$ did not induce any increase in $[Ca^{2+}]_i$ by itself, it increased the frequency and amplitude of $[Ca^{2+}]_i$ oscillations caused by 10 pM CCK-8S. However, $30\;{\mu}M\;H_2O_2$ had little effect on 1 nM CCK-8S-induced increase in $[Ca^{2+}]_i$. ROS scavenger, 1 mM N-acetylcysteine, did not affect $[Ca^{2+}]_i$ changes induced by 10 pM or 1 nM CCK-8S. Therefore, it was concluded that $30\;{\mu}M\;H_2O_2$ enhanced low concentration of CCK-8S-induced amylase release probably by increasing $[Ca^{2+}]_i$ oscillations while it inhibited high concentration of CCK-8S-induced amylase release.

• The Korean Journal of Physiology
• /
• v.2 no.1
• /
• pp.47-52
• /
• 1968

Twenty white rabbits anesthetized with nembutal (30 mg/kg) were employed in this experiment. Five of them served as controls; the remaining rabbits as experimental group were subjected to irreversible hemorrhagic shock. Shock was induced by bleeding the animals until mean blood pressure decreased to a level of 50-40 mmHg. This level of pressure was maintained for 3-4 hours, after which the drawn blood was reinfused. The reinfusion of blood caused the elevation of arterial pressure almost the control level for some minutes, after which a gradual and progressive decline of blood pressure became evident. This decline was thought to be the result from irreversible hemorrhagic shock. When mean blood pressure declined to less than 50 mmHg, chest was opened and samples of arterial blood and left ventricular muscle were taken. Left ventricular muscle and blood plasma were analyzed for potassium, sodium, chloride and water content. Blood glucose concentration was determined by Somogyi-Nelson's method. Extracellular and intracellular myocardial water and electrolyte content were calculated on the basis that electrolytes are distributed between plasma water and interstitial water according to Gibbs-Donnan equilibrium. In this calculation extracellular water was substituted for Na space. The findings obtained were as follows: 1. The concentration of blood glucose was 87mg% in the controls and it rose to 222 mg% in shock (P<0.01). 2. Plasma potassium elevated significantly from 3.3 mEq/l in controls to 8.0 mEq/l in shock (P<0.01), while small decreases in sodium (151-146 mEq/l) and chloride (102-96 mEq/l) were observed (P<0.3, P<0.1), 3. The changes of blood water content (83.1-84.3%) and cardiac water content (77.5-78.3 gm/100gm WT) were observed. 4. In control animals myocardial potassium levels which averaged 30.2 mEq/100 gmDT rose significantly to 40.3 mEq/100 gmDT in shock (P<0.01), while moderate decreases in sodium(16.3-14.3 mEq/100 gmDT) were observed in shock. 5. The calculated transmembrane resting potential of left ventricular muscle of control animals averaged 95 mV, while rabbits in shock averaged 77 mV. (P <0.01). The findings of this experiment do not correspond with the conclusions that myocardial depression seems to be the cause of irreversible hemorrhagic shock, because the excitability of heart muscle is elevated. From the point of view that the lowered transmembrane resting potential, the cause of death in terminal stage of irreversible hemorrhagic shock may be ventricular fibrillation. It can't be said, however, that the lowered transmembrane resting potential is responsible for the transition from reversible to irreversible hemorrhagic shock. The marked increase in blood glucose suggested that glycogenolysis in the liver is favorably active in shock.

• Applied Biological Chemistry
• /
• v.33 no.3
• /
• pp.239-246
• /
• 1990

Monascus anka strains with higher pigment production were developed using UV mutation and natural selection. To obtain organic solvent soluble pigments from Monascus anka, the following culture conditions were compared : standing and shaking culture with Nishikawa's medium, and shaking culture with Lin's medium. Shaking culture in Lin's medium exhibited decrease in solvent-soluble intracellular pigments after initial increase. The decrease was accompanied by the increase in water-soluble extracellular pigments. Monascus anka preferred sucrose and ethanol among 7 carbon sources tested. Treatment of sterol biosynthesis inhibitors, $({\pm})$-miconazole and chlorocholine chloride(CCC) , directed carbon pool to the biosynthetic pathway leading to the pigments with CCC's more pronounced effect. Two dimensional TLC revealed at least 7 yellow pigments suggesting existence of hereto unreported pigment. One of the most abundant yellow pigments was isolated and found to be ankaflavin by NMR and MS analysis.

• Biomedical Science Letters
• /
• v.14 no.2
• /
• pp.69-76
• /
• 2008

${\gamma}$-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the central nervous system, and its actions are mediated by subtypes of GABA receptors named as $GABA_A$, $GABA_B,\;and\;GABA_C,\;GABA_A$, receptor consisting of ${\alpha},\;{\beta},\;{\gamma}\;and\;{\delta}$ subunits is a heterooligomeric ligand-gated chloride channel. This study was performed to investigate regulation of $GABA_A$ receptor by protein kinase C(PKC). Ion currents were recorded using gramicidine-perforated patch and whole cell patch clamp. mRNA encoding the subunits of PKC expressed in major pelvic ganglion (MPG) neurons was detected by using RT-PCR. The GABA-induced inward current was increased by PKC activators and decreased by PKC inhibitors, respectively. These effects were not associated with intracellular $Ca^{2+}$ and GAG (1-oleoyl-2-acetyl-sn-glycerol), a membrane permeable diacylglycerol (DAG) analogue. These results mean that the subfamily of PKC participating in activation of $GABA_A$ receptor would be an atypical PKC (aPKC). Among theses, ${\xi}$ isoform of aPKC was detected by RT-PCR. Taking together, we suggest that excitable $GABA_A$ receptor in sympathetic MPG neuron seemed to be regulated by aPKC, particular in ${\xi}$ isoform. The regulatory roles of PKC on excitatory $GABA_A$ receptors in sympathetic neurons of MPG may be an important factor to control the functional activity of various pelvic organs such as bowel movement, micturition and erection.

• Journal of Korean Neurosurgical Society
• /
• v.59 no.6
• /
• pp.544-550
• /
• 2016

Objective : Cerebral endothelial cells have unique biological features and are fascinating candidate cells for stroke therapy. Methods : In order to understand the molecular mechanisms of human cerebral endothelial cell (hCMEC/D3) transplantation in a rat stroke model, we performed proteomic analysis using 2-dimensional electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Protein expression was confirmed by quantitative real-time PCR and Western blot. Results : Several protein spots were identified by gel electrophoresis in the sham, cerebral ischemia (CI), and CI with hCMEC/D3 treatment cerebral ischemia with cell transplantation (CT) groups, and we identified 14 differentially expressed proteins in the CT group. Proteins involved in mitochondrial dysfunction (paraplegin matrix AAA peptidase subunit, SPG7), neuroinflammation (peroxiredoxin 6, PRDX6), and neuronal death (zinc finger protein 90, ZFP90) were markedly reduced in the CT group compared with the CI group. The expression of chloride intracellular channel 4 proteins involved in post-ischemic vasculogenesis was significantly decreased in the CI group but comparable to sham in the CT group. Conclusion : These results contribute to our understanding of the early phase processes that follow cerebral endothelial cell treatment in CI. Moreover, some of the identified proteins may present promising new targets for stroke therapy.

• CELLMED
• /
• v.4 no.2
• /
• pp.12.1-12.12
• /
• 2014

Epinephrine is a critical drug for patients at risk for anaphylaxis. Here, we suggest moxibustion as an alternative method to reduce anaphylaxis. Moxibustion was applied to the Shimen (CV5) acupoint and found to attenuate compound 48/80-induced mortality. Capsazepine, a transient receptor potential vanilloid (TRPV) 1 antagonist, significantly improved overall survival rates compared to groups treated with moxibustion or 2-aminoethoxydiphenyl borate (an activator of TRPV1, 2, and 3). Probenecid (a TRPV2 agonist) also increased survival rate and reduced histamine levels. Survival rates increased by moxibustion and probenecid were completely inhibited by ruthenium red (a TRPV2 and 3 antagonist) and gadolinium chloride (general TRPV antagonist), respectively. Passive cutaneous anaphylaxis and ear swelling were significantly reduced by moxibustion and probenecid (p < 0.05). In cardiomyocytes, TRPV2 was over-expressed by compound 48/80 and histamine but this increased TRPV2 expression decreased to baseline with moxibustion and probenecid treatment. In addition, intracellular calcium levels increased by compound 48/80 were reduced by probenecid. Overall, these findings suggest that the reduction of anaphylaxis caused by moxibustion could represent a new mechanism of moxibustion related to the regulation of TRPV2 activation and promotion of epinephrine secretion.

• Biomolecules & Therapeutics
• /
• v.22 no.4
• /
• pp.314-320
• /
• 2014

This study was investigated to know whether pachymic acid (PA), one of the predominant triterpenoids in Poria cocos (Hoelen) has the sedative-hypnotic effects, and underlying mechanisms are mediated via ${\gamma}$-aminobutyric acid (GABA)-ergic systems. Oral administration of PA markedly suppressed locomotion activity in mice. This compound also prolonged sleeping time, and reduced sleep latency showing synergic effects with muscimol (0.2 mg/kg) in shortening sleep onset and enhancing sleep time induced by pentobarbital, both at the hypnotic (40 mg/kg) and sub-hypnotic (28 mg/kg) doses. Additionally, PA elevated intracellular chloride levels in hypothalamic primary cultured neuronal cells of rats. Moreover, Western blotting quantitative results showed that PA increased the amount of protein level expression of $GAD_{65/67}$ over a broader range of doses. PA increased ${\alpha}$- and ${\beta}$-subunits protein levels, but decreased ${\gamma}$-subunit protein levels in $GABA_A$ receptors. The present experiment provides evidence for the hypnotic effects as PA enhanced pentobarbital-induced sleeping behaviors via $GABA_A$-ergic mechanisms in rodents. Taken together, it is proposed that PA may be useful for the treatment of sleep disturbed subjects with insomnia.

• Microbiology and Biotechnology Letters
• /
• v.5 no.3
• /
• pp.133-140
• /
• 1977

The results of electron microscopic studies on the cell fine structure of Nocardia sp the location of tellurite-reducing enzyme and the reduction part of T. T. C. (Triphenyl tetrazonium chloride) were summarized as follows. As the fine structure of the cell, the membrane-like structure with unit membrane was distributed in the cytoplasm. The membrane-like structure had complicate forms: some of membrane-like structure appeared spiral form. As the metal tellurium salt appeared in the cytoplasm, it is obvious that tellurite and tellurate-reducing enzymes are present in the cytoplasm. Reduction of T. T. C. took place in the cell membrane and the intracellular membrane-like structure. Therefore, it was thought that reduction of tellurate and T. T. C. took place in different parts. T. T. C. formazane formed in the cell was reoxidized by osmic acid which was used as a fixation reagent for the electron microscopic specimen preparation. As 95％ T. T. C. formazane was soluble in ethanol and embedding materials and removed out of the cell, an originally formed formazane appeared as electron light part on the electron microscopic image.

• Natural Product Sciences
• /
• v.23 no.1
• /
• pp.40-45
• /
• 2017

Epilepsy is a brain disorder that affects millions of people worldwide. It is characterized by recurrent and unpredictable seizures that are usually controlled with antiepileptic/anticonvulsive drugs. However, most antiepileptic drugs produce various side effects such as tolerance and sedation. Thus, there is a growing interest for alternative anticonvulsive drugs, preferably from natural or herbal sources. In this study, we evaluated the anticonvulsive effects of Rehmannia glutinosa (RG). The anticonvulsive effect of RG extract was evaluated using electroshock- and chemical-induced seizure tests in mice. To identify its probable mechanism of action, the effects of RG extract on $Cl^-$ influx was measured in vitro. We found that RG extract has anticonvulsive effects against electroshock-induced seizures, as indicated by an increased seizure threshold in mice. The RG extract also decreased the percentage of seizure responses induced by the GABAergic antagonist, pentylenetetrazole. These results suggest that the anticonvulsive effects of RG extract are mediated through a GABAergic mechanism. In support of this mechanism, our in vitro test showed that RG extract increases intracellular $Cl^-$ influx. Furthermore, RG extract did not show sedative and/or muscle relaxant effects in the open-field and rota-rod tests. Altogether, these results confirm that RG extract could be a herbal anticonvulsant and a potential alternative for clinical use.

• Reproductive and Developmental Biology
• /
• v.33 no.4
• /
• pp.237-242
• /
• 2009

Pregnancy is a unique event in which a fetus develops in the uterus despite being genetically and immunologically different from the mother, and the underlying mechanisms remain poorly understood. To analyze the differential gene expression profiles in nonpregnant and 7 days post coitus (dpc) pregnant uterus of mice, we performed a global proteomic study by 2-D gel electrophoresis (2-DE) and MALDI-TOF-MS. The uterine proteins were separated using 2-DE, Approximately 1,000 spots were detected on staining with Coomassie brilliant blue. An image analysis using Melanie III (Swiss Institute for Bioinformatics) was performed to detect variations in protein spots between pregnant and nonpregnant uterus. Twenty-one spots were identified as differentially expressed proteins, of which 10 were up-regulated proteins such as alpha-fetoprotein, chloride intracellular channel 1, transgelin, heat-shock protein beta-1, and carbonic anhydrase II, while 11 were down-regulated proteins such as X-box binding protein, glutathione S-transferase omega 1, olfactory receptor Olfr204, and metalloproteinase-disintegrin domain containing protein TECADAM. Most of the identified proteins appeared to be related with catabolism, cell growth, metabolism, regulation, cell protection, protein repair, or protection. Our results uncovered key proteins of mouse uterus involved in pregnancy.