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1.
Article in English | WPRIM | ID: wpr-727866

ABSTRACT

Bladder dysfunction is a common complication of diabetes mellitus (DM). However, there have been a few studies evaluating bladder smooth muscle contraction in DM in the presence of pharmacological inhibitors. In the present study, we compared the contractility of bladder smooth muscle from normal rats and DM rats. Furthermore, we utilized pharmacological inhibitors to delineate the mechanisms underlying bladder muscle differences between normal and DM rats. DM was established in 14 days after using a single injection of streptozotocin (65 mg/kg, intraperitoneal) in Sprague-Dawley rats. Bladder smooth muscle contraction was induced electrically using electrical field stimulation consisting of pulse trains at an amplitude of 40 V and pulse duration of 1 ms at frequencies of 2–10 Hz. In this study, the pharmacological inhibitors atropine (muscarinic receptor antagonist), U73122 (phospholipase C inhibitor), DPCPX (adenosine A₁ receptor antagonist), udenafil (PDE5 inhibitor), prazosin (α₁-receptor antagonist), verapamil (calcium channel blocker), and chelerythrine (protein kinase C inhibitor) were used to pretreat bladder smooth muscles. It was found that the contractility of bladder smooth muscles from DM rats was lower than that of normal rats. In addition, there were significant differences in percent change of contractility between normal and DM rats following pretreatment with prazosin, udenafil, verapamil, and U73122. In conclusion, we suggest that the decreased bladder muscle contractility in DM rats was a result of perturbations in PLC/IP₃-mediated intracellular Ca²⁺ release and PDE5 activity.


Subject(s)
Animals , Atropine , Diabetes Mellitus , Muscle, Smooth , Phosphotransferases , Prazosin , Rats , Rats, Sprague-Dawley , Streptozocin , Type C Phospholipases , Urinary Bladder , Verapamil
2.
Article in English | WPRIM | ID: wpr-715617

ABSTRACT

In this study, we investigated the effects of pelargonidin, an anthocyanidin found in many fruits and vegetables, on endothelium-independent vascular contractility to determine the underlying mechanism of relaxation. Isometric contractions of denuded aortic muscles from male rats were recorded, and the data were combined with those obtained in western blot analysis. Pelargonidin significantly inhibited fluoride-, thromboxane A2-, and phorbol ester-induced vascular contractions, regardless of the presence or absence of endothelium, suggesting a direct effect of the compound on vascular smooth muscles via a different pathway. Pelargonidin significantly inhibited the fluoride-dependent increase in the level of myosin phosphatase target subunit 1 (MYPT1) phosphorylation at Thr-855 and the phorbol 12,13-dibutyrate-dependent increase in the level of extracellular signal-regulated kinase (ERK) 1/2 phosphorylation at Thr202/Tyr204, suggesting the inhibition of Rho-kinase and mitogen-activated protein kinase kinase (MEK) activities and subsequent phosphorylation of MYPT1 and ERK1/2. These results suggest that the relaxation effect of pelargonidin on agonist-dependent vascular contractions includes inhibition of Rho-kinase and MEK activities, independent of the endothelial function.


Subject(s)
Animals , Anthocyanins , Aorta , Blotting, Western , Endothelium , Fluorides , Fruit , Humans , Isometric Contraction , Male , Muscle, Smooth, Vascular , Muscles , Myosin-Light-Chain Phosphatase , Phosphorylation , Phosphotransferases , Protein Kinases , Rats , Relaxation , rho-Associated Kinases , Vasoconstriction , Vegetables
3.
Article in English | WPRIM | ID: wpr-717999

ABSTRACT

A comprehensive collection of proteins senses local changes in intracellular Ca²⁺ concentrations ([Ca²⁺](i) and transduces these signals into responses to agonists. In the present study, we examined the effect of sphingosine-1-phosphate (S1P) on modulation of intracellular Ca²⁺ concentrations in cat esophageal smooth muscle cells. To measure [Ca²⁺](i) levels in cat esophageal smooth muscle cells, we used a fluorescence microscopy with the Fura-2 loading method. S1P produced a concentration-dependent increase in [Ca²⁺](i) in the cells. Pretreatment with EGTA, an extracellular Ca²⁺ chelator, decreased the S1P-induced increase in [Ca²⁺](i), and an L-type Ca²⁺-channel blocker, nimodipine, decreased the effect of S1P. This indicates that Ca²⁺ influx may be required for muscle contraction by S1P. When stimulated with thapsigargin, an intracellular calcium chelator, or 2-Aminoethoxydiphenyl borate (2-APB), an InsP₃ receptor blocker, the S1P-evoked increase in [Ca²⁺](i) was significantly decreased. Treatment with pertussis toxin (PTX), an inhibitor of G(i)-protein, suppressed the increase in [Ca²⁺](i) evoked by S1P. These results suggest that the S1P-induced increase in [Ca²⁺](i) in cat esophageal smooth muscle cells occurs upon the activation of phospholipase C and subsequent release of Ca²⁺ from the InsP₃-sensitive Ca²⁺ pool in the sarcoplasmic reticulum. These results suggest that S1P utilized extracellular Ca²⁺ via the L type Ca²⁺ channel, which was dependent on activation of the S1P₄ receptor coupled to PTX-sensitive G(i) protein, via phospholipase C-mediated Ca²⁺ release from the InsP₃-sensitive Ca²⁺ pool in cat esophageal smooth muscle cells.


Subject(s)
Animals , Calcium , Cats , Egtazic Acid , Fura-2 , Methods , Microscopy, Fluorescence , Muscle Contraction , Muscle, Smooth , Myocytes, Smooth Muscle , Nimodipine , Pertussis Toxin , Phospholipases , Sarcoplasmic Reticulum , Thapsigargin , Type C Phospholipases
4.
Article in English | WPRIM | ID: wpr-728271

ABSTRACT

Ribosomal S6 kinase is a family of serine/threonine protein kinases involved in the regulation of cell viability. There are two subfamilies of ribosomal s6 kinase, (p90rsk, p70rsk). Especially, p90rsk is known to be an important downstream kinase of p44/42 MAPK. We investigated the role of p90rsk on ethanol-induced cell proliferation of HepG2 cells. HepG2 cells were treated with 10~50 mM of ethanol with or without ERK and p90rsk inhibitors. Cell viability was measured by MTT assay. The expression of pERK1, NHE1 was measured by Western blots. The phosphorylation of p90rsk was measured by ELISA kits. The expression of Bcl-2 was measured by qRT-PCR. When the cells were treated with 10~30 mM of ethanol for 24 hour, it showed significant increase in cell viability versus control group. Besides, 10~30 mM of ethanol induced increased expression of pERK1, p-p90rsk, NHE1 and Bcl-2. Moreover treatment of p90rsk inhibitor attenuated the ethanol-induced increase in cell viability and NHE1 and Bcl-2 expression. In summary, these results suggest that p90rsk, a downstream kinase of ERK, plays a stimulatory role on ethanol-induced hepatocellular carcinoma progression by activating anti-apoptotic factor Bcl-2 and NHE1 known to regulate cell survival.


Subject(s)
Blotting, Western , Carcinoma, Hepatocellular , Cell Proliferation , Cell Survival , Enzyme-Linked Immunosorbent Assay , Ethanol , Hep G2 Cells , Humans , Phosphorylation , Phosphotransferases , Protein Kinases , Ribosomal Protein S6 Kinases
5.
Article in Korean | WPRIM | ID: wpr-121731

ABSTRACT

OBJECTIVE: Online pharmacies were introduced in some countries such as United States of America or Canada. They can provide benefits to consumer because they can buy and take conveniently drugs without limitation of location or time. In Korea, online pharmacies are illegal and only pharmacists can sell drugs to consumers or patients. Therefore, we investigated the knowledge of online pharmacy and the possible problem in Korea to survey pharmacists. METHODS: We developed questionnaire based on previous articles about online pharmacy and surveyed nation-wide pharmacists by mail or e-mail. The data was analyzed by SPSS and Microsoft Excel. P-values less than 0.05 were statistically significant. RESULTS: 175 pharmacists involved in this study. About introduction of online pharmacies, 53.1% were opposition while 10.3% were approval and 36.6% were conditional. Although online pharmacies were introduced, 46.3% pharmacists do not have a plan to start online pharmacy. However, the approval and tends about starting online pharmacies were higher in younger pharmacists (20s, 30s) (p < 0.05). The criteria of permission about opening online pharmacies were 100% pharmacist license regardless of holding off-line pharmacy. 53.7% pharmacists responded education about taking medication is impossible. When online pharmacies are introduced, 65.1% pharmacists responded traditional pharmacies are affected negatively. Pharmacists concerned that the competition with large-sized distribution corporations, reduced reliance between pharmacists and patients, illegal transaction of counterfeit drugs, increased misuse of drugs. CONCLUSION: These results showed that Korea pharmacists have negative standard on online pharmacies. Therefore it is required to be more cautious before introducing online pharmacy and it need strict watching system and continuous education and study for safety after introducing online pharmacy.


Subject(s)
Americas , Canada , Counterfeit Drugs , Education , Electronic Mail , Humans , Internet , Korea , Licensure , Pharmaceutical Services, Online , Pharmacies , Pharmacists , Pharmacy , Postal Service , Public Health , United States
6.
Article in English | WPRIM | ID: wpr-727669

ABSTRACT

The purpose of this study is to characterize the effects of KHG26792 (3-(naphthalen-2-yl(propoxy) methyl)azetidine hydrochloride), a potential skin whitening agent, on melanin synthesis and identify the underlying mechanism of action. Our data showed that KHG26792 significantly reduced melanin synthesis in a dose-dependent manner. Additionally, KHG26792 downregulated microphthalmia-associated transcription factor (MITF) and tyrosinase, the rate-limiting enzyme in melanogenesis, although tyrosinase was not inhibited directly. KHG26792 activated extracellular signal-regulated kinase (ERK), whereas an ERK pathway inhibitor, PD98059, rescued KHG26792-induced hypopigmentation. These results suggest that KHG26792 decreases melanin production via ERK activation. Moreover, the hypopigmentary effects of KHG26792 were confirmed in a pigmented skin equivalent model using Cervi cornus Colla (deer antler glue), in which the color of the pigmented artificial skin became lighter after treatment with KHG26792. In summary, our findings suggest that KHG26792 is a novel skin whitening agent.


Subject(s)
Animals , Antlers , Cornus , Hypopigmentation , MAP Kinase Signaling System , Melanins , Microphthalmia-Associated Transcription Factor , Monophenol Monooxygenase , Phosphotransferases , Skin Lightening Preparations , Skin , Skin, Artificial
7.
Article in English | WPRIM | ID: wpr-727494

ABSTRACT

This study investigated effect of extract containing quercetin-3-O-beta-D-glucuronopyranoside from Rumex Aquaticus Herba (ECQ) against chronic gastritis in rats. To produce chronic gastritis, the animals received a daily intra-gastric administration of 0.1 ml of 0.15% iodoacetamide (IA) solution for 7 days. Daily exposure of the gastric mucosa to IA induced both gastric lesions and significant reductions of body weight and food and water intake. These reductions recovered with treatment with ECQ for 7 days. ECQ significantly inhibited the elevation of the malondialdehyde levels and myeloperoxidase activity, which were used as indices of lipid peroxidation and neutrophil infiltration. ECQ recovered the level of glutathione, activity of superoxide dismutase (SOD), and expression of SOD-2. The increased levels of total NO concentration and iNOS expression in the IA-induced chronic gastritis were significantly reduced by treatment with ECQ. These results suggest that the ECQ has a therapeutic effect on chronic gastritis in rats by inhibitory actions on neutrophil infiltration, lipid peroxidation and various steps of reactive oxygen species (ROS) generation.


Subject(s)
Animals , Body Weight , Drinking , Gastric Mucosa , Gastritis , Glutathione , Iodoacetamide , Lipid Peroxidation , Malondialdehyde , Neutrophil Infiltration , Peroxidase , Quercetin , Rats , Reactive Oxygen Species , Rumex , Superoxide Dismutase
8.
Article in English | WPRIM | ID: wpr-727344

ABSTRACT

We have shown that myosin light chain kinase (MLCK) was required for the off-contraction in response to the electrical field stimulation (EFS) of feline esophageal smooth muscle. In this study, we investigated whether protein kinase C (PKC) may require the on-contraction in response to EFS using feline esophageal smooth muscle. The contractions were recorded using an isometric force transducer. On-contraction occurred in the presence of NG-nitro-L-arginine methyl ester (L-NAME), suggesting that nitric oxide acts as an inhibitory mediator in smooth muscle. The excitatory composition of both contractions was cholinergic dependent which was blocked by tetrodotoxin or atropine. The on-contraction was abolished in Ca2+-free buffer but reappeared in normal Ca2+-containing buffer indicating that the contraction was Ca2+ dependent. 4-aminopyridine (4-AP), voltage-dependent K+ channel blocker, significantly enhanced on-contraction. Aluminum fluoride (a G-protein activator) increased on-contraction. Pertussis toxin (a Gi inactivator) and C3 exoenzyme (a rhoA inactivator) significantly decreased on-contraction suggesting that Gi or rhoA protein may be related with Ca2+ and K+ channel. ML-9, a MLCK inhibitor, significantly inhibited on-contraction, and chelerythrine (PKC inhibitor) affected on the contraction. These results suggest that endogenous cholinergic contractions activated directly by low-frequency EFS may be mediated by Ca2+, and G proteins, such as Gi and rhoA, which resulted in the activation of MLCK, and PKC to produce the contraction in feline distal esophageal smooth muscle.


Subject(s)
4-Aminopyridine , Aluminum , Aluminum Compounds , Atropine , Azepines , Benzophenanthridines , Contracts , Esophagus , Fluorides , GTP-Binding Proteins , Muscle, Smooth , Myosin-Light-Chain Kinase , NG-Nitroarginine Methyl Ester , Nitric Oxide , Pertussis Toxin , Protein Kinase C , rhoA GTP-Binding Protein , Tetrodotoxin , Transducers
9.
Article in English | WPRIM | ID: wpr-727521

ABSTRACT

It was evaluated the inhibitory action of quercetin-3-O-beta-D-glucuronopyranoside (QGC) on reflux esophagitis and gastritis in rats. QGC was isolated from the herba of Rumex Aquaticus. Reflux esophagitis or gastritis was induced surgically or by administering indomethacin, respectively. Oral QGC decreased ulcer index, injury area, gastric volume, and acid output and increased gastric pH as compared with quercetin. Furthermore, QGC significantly decreased gastric lesion sizes induced by exposing the gastric mucosa to indomethacin. Malondialdehyde levels were found to increase significantly after inducing reflux esophagitis, and were reduced by QGC, but not by quercetin or omeprazole. These results show that QGC can inhibit reflux esophagitis and gastritis in rats.


Subject(s)
Animals , Esophagitis, Peptic , Gastric Mucosa , Gastritis , Hydrogen-Ion Concentration , Indomethacin , Lipid Peroxidation , Malondialdehyde , Omeprazole , Quercetin , Rats , Rumex , Ulcer
10.
Article in English | WPRIM | ID: wpr-727779

ABSTRACT

Recent data have shown the importance of oxidative stresses in the pathogenesis of inflammatory bowel disease, crohn's disease and ulcerative colitis. H2O2, reactive oxygen species (ROS) donor, has been reported to act as a signaling molecule involved in a variety of cellular functions such as apoptosis and proliferation. In the present study, we investigated viability of cultured ileal smooth muscle cells (ISMC) after stimulation with H2O2. Trypan blue method revealed that the cell viability of ISMC treated with 1 mM H2O2 was not different from that of controls at up to 2 h time point, while treatment of ISMC with 1 mM H2O2 for 48 h finally induced significant decrease in the cell viability. Therefore, we evaluated whether H2O2 was capable of ERKs activation in ISMC for the short-term exposure and examined whether tyrosine kinase was involved in the process of ERK activation by H2O2 in ISMC. We also investigated the effects of H2O2 on activation of SAPK/JNK and p38 MAP kinase in ISMC. Thus, ISMC were cultured and exposed to H2O2, and western blot analysis was performed with phospho- specific MAP kinase antibodies. Robust activation of ERK occurred within 30 min of 1 mM H2O2 treatment. H2O2-induced ERK activation was attenuated by a tyrosine kinase inhibitor, genistein, indicating that tyrosine kinase was probably involved in the ERK activation by H2O2. H2O2 was a moderate activator of SAPK/JNK, while p38 MAP kinase was not activated by H2O2. We suggest that ERK activation induced by short-term H2O2 treatment plays a critical role in cellular protection in the early stage of response to oxidative stress. The present study suggests the necessity of identification of MAPK signaling pathways affected by ROS, since it could ultimately elucidate cellular consequences involved in initiation and perpetuation of intestinal tissue damage in the diseases such as crohn's disease and ulcerative colitis, resulted from excessive ROS.


Subject(s)
Antibodies , Apoptosis , Blotting, Western , Cell Survival , Colitis, Ulcerative , Crohn Disease , Genistein , Humans , Inflammatory Bowel Diseases , Muscle, Smooth , Myocytes, Smooth Muscle , Oxidative Stress , p38 Mitogen-Activated Protein Kinases , Phosphotransferases , Protein-Tyrosine Kinases , Reactive Oxygen Species , Tissue Donors , Trypan Blue
11.
Article in English | WPRIM | ID: wpr-727421

ABSTRACT

This study was aimed to evaluate the effects of quercetin and desferrioxamine on the development of the reflux esophagitis induced surgically, on gastric secretion and on lipid peroxidation which is a marker of oxidative stress. Omeprazole was used as a positive control drug. Omeprazole significantly and dose-dependently prevented the development of reflux esophagitis, but quercetin or desferrioxamine prevented only at high dose. Omeprazole significantly and dose-dependently inhibited the gastric acid secretion (gastric volume, pH and acid output), but quercetin or desferrioxamine did not inhibit. Malonyldialdehyde content, the end product of lipid peroxidation, increased significantly after the induction of reflux esophagitis. Omeprazole prevented lipid peroxidation. Quercetin and desferrioxamine inhibited the lipid peroxidation independent of their actions on gastric secretion. This result indicates that omeprazole confirmed preventing effect of rat reflux esophagitis, but quercetin and desferrioxamine inhibited esophagitis by reduction of lipid peroxidation irrespective of gastric acid secretion.


Subject(s)
Animals , Deferoxamine , Esophagitis , Esophagitis, Peptic , Gastric Acid , Hydrogen-Ion Concentration , Lipid Peroxidation , Malondialdehyde , Omeprazole , Oxidative Stress , Quercetin , Rats
12.
Article in English | WPRIM | ID: wpr-728333

ABSTRACT

We investigated the action of NOS inhibitors on NOS in rats. Both of nitric oxide synthase inhibitors, NG-monomethyl-L-arginine (L-NMMA, 3 micrometer) or NG-nitro-L-arginine methylester (L-NAME, 30 micrometer), augmented phenylephrine (PE, 10-7 M)-induced contraction which was inhibited by acetylcholine (ACh) in rat thoracic aorta. This augmentation by L-NAME or L-NMMA was attenuated with the treatment of NO precursor, arginine. ACh, however, decreased the augmentation induced by L-NMMA, but not by L-NAME. Superoxide dismutase (SOD, 50 u/ml) potentiated an inhibitory effect of ACh on the PE (10-7 M)-induced contraction. It has been known that platelet activating factor itself induces iNOS. Platelet activating factor (PAF, 10-7 M) inhibited PE (10-7 M)-induced contraction. Pretreatment with L-NMMA (30 mM) or L-NAME (30 mM) significantly blocked the inhibitory action of PAF on PE-induced contraction. L-NMMA (100 mM) or L-NAME (100 mM) reduced nerve conduction velocity (NCV) relevant to nNOS in rat sciatic nerve. ACh attenuated the reduction of NCV by L-NMMA-, but not by L-NAME-induced reduction of NCV. These results suggest that L-NMMA and/or L-NAME have different action on three types of NOS in rats.


Subject(s)
Acetylcholine , Animals , Aorta, Thoracic , Arginine , Neural Conduction , NG-Nitroarginine Methyl Ester , Nitric Oxide Synthase , Nitric Oxide , Nitroarginine , omega-N-Methylarginine , Phenylephrine , Platelet Activating Factor , Rats , Sciatic Nerve , Superoxide Dismutase
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